This is my 2nd build. My first one was AD Gragas/Jungle Gragas. When Darius came out I thought he would make a great jungler but my friend thought otherwise. We played a few AI games and to our surprise it worked pretty well. I played more AI games and went on into real games to try and work things out. This Darius build revolves mostly around attack speed and getting 5 stacks of Hemorrhage ASAP. The reason for this I will explain later.

As someone stated before why should you jungle with Darius when he is such a great solo top and even if its possible he isn't that great of a jungler. I have played many different junglers such as AD Gragas jungle (it works very well), to more obvious junglers such as udyr, olaf, fiddlesticks, jax etc. and no one destroys Creep Camps as fast as Darius does even without Wriggle's Lantern.

For example on my level 26 acc, which is built 5-21 atm for jungling, I was able to kill Red Buff at level 2 without the need of Smite with boots, 1 health pot, and around 450 health. I used a potion b4 engaging and used Decimate to engage the fight. attack only the Red Buff using Crippling Strike after the first hit to get stacks on him faster.

After using Crippling Strike 1 or 2 more times the smaller creeps are dead and you should be able to get a lot of auto attacks in using Crippling Strike with the help of Blue Buff and 5 stacks of Hemorrhage. After every auto attack immediately using [[Crippling Strike will refresh the auto attack so u can hit again immediately making if possible to kill Red Buff.

Now I know it seems useless why not to use smite to kill Red Buff but I do it because smite usually is not ready until Red Buffs already almost dead so there is no need to use it and also it gives me a chance to kill the Golem camp next to it with more ease even though I have low health.

Will add videos of this and jungling will come eventually

Pros:

A good ganker with the help of another cc.
A quick jungler
Nice damage output
Amazing ulti
a great sweeper

Cons:

Can't do anything when CC
Easily able to KS (makes rest of your team weak end game)
Easily Kited
Bad ganks W/O or missing with

Apprehend

The reason for playing Darius as an AS champion is because of his Crippling Strike
With enough CDR and you would be dealing massive amount of extra damage each time you use Crippling Strike.
Why?
If you look at it mathematically with 40% cdr, Crippling Strike cool down will be 4.5seconds. with the passive of Crippling Strike when the enemy has 5 stacks the cooldown should reset but unfortunately it does not. But the cd would be a 1 second cool down which makes it still possible to spam that spell like no other.
Now think about it. with Trinity Force every time you use a spell u will deal an extra 150% base damage. add that with using Crippling Strike every second to deal an extra 100% damage. not to mention the enemy would be practically permanently slowed making it almost impossible to get away.

P.S. I was to lazy to rewrite this paragraph so im just going to write it here.
CDR isn't as important as i thought because of the fact that no matter what the lowest u can bring the cooldown is 1 second. However you still need the CDR by using Blue Buff or just buying Elixir of Brilliance

As a heads up Crippling Strike is going to be your friend because of it being a second hit not as a slow. The slow helps a lot but with Trinity Force and/or Frozen Mallet you already have a good slow.

Crippling Strike even at level 1 deals an extra 100% damage and with Sheen or Trinity Force you deal over 250% damage on an instant second hit you can use every second once the enemy has 5 stacks.

Im not to sure if these runes would be best for Darius but this is what i have so far. If u have a better idea on what runes I should use please post it and i will think about changing it.

Greater Mark of Attack Damage The extra damage works wonder for you because everything is based off of AD

Greater Seal of Defense Its nice to have the extra armor to be able to withstand more hits from minions and other ad champions

Greater Glyph of Attack Speed As i said earlier you want as much AS so u can get those 5 Hemorrhage on them as quick as possible.

Greater Quintessence of Movement Speed for the extra boost of speed that you will need throughout the game for quicker mobility in ganks and chasing.

Other runes

Greater Glyph of Scaling Magic Resist If you want more survivability or you don't see the point of extra attack speed.

The reason for going 9/21/0 instead of 21/9/0 is because i wanted to get the extra movement speed from Initiator . Especially in early game ganks Darius Needs that extra movement speed to be able to gank well.

If you would prefer to deal more damage than this mastery build would be better.

to start off with and 3 you need to make sure u get a good leash at blue so you don't need to use a potion or using one and having near full health after blue golem is dead.

The reason for this item is because of all stats/slow/ and the extra base 150% damage which goes well when u have a good amount of cdr.

Darius needs the tenacity to be able to even try to gank or engage in any fight

Zeke's Herald With the Cdr, attack speed, and life steal its a good item imo

The extra health for better sustainability

gives a very nice attack output and the crit helps a lot endgame

Imo one of the best items for those that need to move fast and attack even faster

For those games that you have so much money endgame you don't know what to do with it.

You can get rid of Mercury's Treads for another Phantom Dancer. by endgame you should be buying . You don't lose any movement speed but u do lose the tenacity so only do this if they have very little CC

Other items

You can use this item instead of Warmog's Armor it may seem wierd with having a Trinity Force but it still works about because the Trinity Force proc replaces Frozen Mallet proc whenever its used. Trinity Force is a must however because it gives a massive damage boost.

Blood Thirster In exchange for Zeke's Herald.

You can add wriggles lantern in the build if you like. The reason why I do not get it is because I want to rush a Trinity Force as fast as possible or at least get 1 1/2 - 2 of the item requirements before getting a Vampiric Scepter for the lifesteal.

Now the Cons for not getting a Wriggle's Lantern there are 3 main Cons.

1.You do not get the proc.
2.No early Lifesteal.
3.No free wards.

Now the reasons why i do not get the item anyways

1.Sheen+Crippling Strike= you have a reliable massive damage already
2.Grab some extra potions now and then until you get Vampiric Scepter for life gain
3.Just buy some wards or I am usually playing with a friend who grabs the wards himself.

Before we talk about Skill sequence lets talk about the skills themselves

A very nice Dot with every basic attack and also helps when using Crippling Strike

A great AoE damage dealer and good for clearing out creep waves and putting Hemorrhage on enemy champions from a short distance.

A really great boost of damage with a great cd when enemy's have 5 Hemorrhage. This will become your main spell mid-end game This is not the main spell just because of the slow it is the main spell because of the massive damage boost it gives you every second if used properly making it possible to hit 2-3 times per second because it refreshes your attack. the slow does help a lot especially with Trinity Force and Frozen Mallet

a mini grab similar to Rocket Grab but shorter and grabs everyone in the arc.

an amazing damage output because its true damage and deals the most damage when there are 5 Hemorrhage on the enemy champion + an instant refresh when it kills an enemy champion. (amazing skill but if used to often to kill it will harm the team)

There are two ways to do skill sequence that are different only in the first 4 levels
This is for when you see an opportunity to gank immediately once you hit level 3

If you can't see a good opportunity to gank a lane and it would be better to jungle a bit longer it would be better to chose

Other than the first 4 spells the rest of the sequence is the same

The needed spell for a jungler (other than maybe Warwick)

I use instead of to give me more flexibility when i am engaging for a gank. to be able to get in close range when they are running away or when engaging depending on who's in the lane

Alternatives
Ghost is the only real alternative to flash and it depends on the player IMO on which one is used.

Like most junglers you will start off at blue to give you the extra cdr to spam your spells more. once level 2 (right after blue) make sure u are using Crippling Strike properly. by this I mean to use it immediately after your basic attack hits to refresh your attack speed and get a 2nd hit in. It is best to use it when the creep has 5 Hemorrhage on them so that you can use the spell again 2seconds later (if you have blue) continue on and get wreaths and if able red buff.

This is where you make the decision of your spell sequence and if you are going to gank or continue jungling till level 4 before going for a gank.

Ganking with Darius is harder than most other junglers because he does not have a good CC. the
way to gank differs depending on who is your teammate in the lane

Lane with Champion(s) that have any good CC
Let your teammate initiate. once they go in for the CC run in and use Decimate once it is in range and just auto attack once or twice before using your Crippling Strike to reduce the cooldown to use it again. if/when they flash/ghost grab them back in with Apprehend or Flash before doing so. if they have not died by then your Crippling Strike should be up again to slow them down.

Lanes w/o a good CC
There are a few ways to try this out.

Initiate with Flash to immediate Decimate 1 auto attack and Crippling Strike when they try to escape hopefully you'll be in range for Apprehend.

If enemy champion is low in health
Initiate with Apprehend to a Crippling Strike and Decimate.

Or let your teammate initiate and either rush in with Decimate to Crippling Strike or if your teammate is trying to lure them wait and gank once you're behind them.

These are just a few ways to gank with Darius and ganking is situational and no best one way to gank with Darius.

Once level 6 ganking becomes much easier because of your massive increase in damage output with Noxian Guillotine Like any gank initiate in whichever way you feel most comfortable with. Hopefully you'll have your buffs and with enough stacks of your passive Crippling Strike will become your best friend along with Trinity Force. With and some potions you should be able to kill dragon at level 7 and make sure you have blue to Crippling Strike and Decimate.
Warning:Do not KS with Noxian Guillotine. As much as being fed is nice make sure u let your teammates have kills or your team will be weak by endgame and with this build Darius is not the best of carrys.

Just grab your buffs now and then when they get up and make sure you are grabbing dragon which should die very quickly by now. Stay with the team and do not initiate on your own. Let your tank take the damage and go for one hero at a time to spam Crippling Strike while using Decimate to deal the AoE damage. You want to take down enemy heroes as fast as possible so screw ksing and if u see a chance to kill them with Noxian Guillotine you do it. Noxian Guillotine should deal about 800dmg+ of true damage with 5 stacks which, with your attack speed, shouldn't be to hard to achieve.

If you are new to jungling I suggest looking at
http://www.mobafire.com/league-of-legends/build/jungling-101-what-you-need-to-know-77704

He gives great advice on the basics of jungling as well as the spawn times of the camps also a broad range of Champions to jungle with

And also thanks to jhoijhoi for his
http://www.mobafire.com/league-of-legends/build/making-a-guide-101506#chapter5

which has helped me write this guide

This is just my first video I've made and its mostly random kills and deaths. The music in it was as a joke to a friend so don't mind it to much.
http://www.youtube.com/watch?v=hBxSV8hJBGg Play Video
*Video of an actual jungle will come out soon*