Welcome!

This is my first guide so feel free to offer me some constructive criticism. This guide is for Udyr, without a doubt my favorite champion. If you enjoy destroying enemy teams, dominating every lane and the jungle, this guide should work for you. Keep in mind that this is for Wilding Claw jungle Udyr. I personally prefer using Tiger Stance to jungle because of the high single target damage. Wingborne Storm however is a safer way to go and the jungle clears are much quicker. Though with the upcoming experience changes these jungle clears may be less important.
tl;dr Wilding Claw and Wingborne Storm are both viable and strong. It is all YOUR decision to decide which one is better.


IN THE TOP TEN UDYR GUIDES
WAT

EDIT: Season 3 is here and this guide will be getting an item overhaul, might be a while since I have to do some testing. I'll give you all the new masteries for now but those will probably change. For some reason they're the same as one another.

Pros:

-Fast
-Can be a tank while dealing massive damage
-Quick jungle route
-Able to disrupt enemy jungle
-Plays a large role in fights

Cons:

-No range
-Ganks rely on lane partner crowd control or red buff
-Wards will ruin ganks

Same goes for Wingborne Storm except the clear times and farming capability are faster and higher (respectively) while Tiger has better ganking potential in addition to being more fun.

The following masteries are the ones I find the most successful:
9/21/0
0/21/9
21/0/9 (Very risky)

I have seen Wilding Claw guides say 9/12/9 work but I am a tad skeptical and have yet to try this.

For Marks I use Greater Mark of Attack Damage because the AD helps with Wilding Claw.

As far as Seals go I can't see anything else being used other than Greater Seal of Armor simply because it makes the jungle much safer.

Same with Glyphs except I like flat magic resist, you can also try Greater Glyph of Scaling Magic Resist for better late game magic resist.

Quintessences are really your decision, I personally prefer movement speed over anything else.

These are very easy to understand.
Kill minions, steal buffs etc.
This has gotten me out of sticky situations feel free to try something else though.

Flash and Smite are non negotiable, the reason why Ghost isn't viable is because you need to should be able to jump into their enemy team and start team fights with the help of Blazing Stampede and Flash allows you to do that.

Before I start explaining my item choices, please be aware that I cannot tell you what to build every match as that changes with the enemy team and the performance of each player. This is my standard build because I annihilate with Wilding Claw because of the high single target damage. Yes this build is outrageously expensive.

Your starting items should be:

with one
or
with five < Only get that if you're going to get Wriggle's Lantern which is only worth it if you're doing well.

I start with the Regrowth because it doesn't hurt your jungling speed and gives you some nice sustain in the jungle when stacked with your Iron Mantle and you can build it into a Philosopher's Stone which is great because then you have the mana to give your blue buffs to your mid lane.

As for boots I either take Ninja Tabi or Mercury's Treads because they provide the needed resistance, according to the enemy team composition. In other words for an AD heavy team buy Ninja Tabi and for an AP or CC heavy team buy Mercury's Treads. Try to build to the strongest player on their team.

Onto the core items, as far as I am concerned Udyr is very flexible with builds as long as you cater to the following stats:
-Health
-Armor
-Magic Resist
-Movement Speed
-Attack Damage

This is why I get Trinity Force because it's a good item overall and shouldn't be too hard to afford with ganks like Tiger Udyr. Aegis of the Legion is a phenomenal item and should be picked up without hesitation. The build I list in the Wilding Claw jungle portion of the guide is purely just good core items and starting items, as I said before Udyr is flexible with items. Something I have been meaning to try (someone please let me know if you have any remote success with this) is to get two Doran's Blade early on after the philosopher's stone I don't know why but it piqued my interest.

As for Wingborne Storm jungle, I can't say much about items. Though your most important item is Wit's End however after that your build should be based on your and the enemy team composition. You should also pick up a Heart of Gold because the gold per 5 is very useful and helps out with farm.

In my honest opinion, Wilding Claw > Wingborne Storm.
This is because Tiger is better for ganks and for quickly taking the larger minions, as most of the money from this build comes from ganks. Wingborne Storm is completely viable and strong, this is my personal preference. Now onto the other stances.


This is great for sustain and can shield a lot of burst when you get some resistances. Due to this I max this second.


You can max this second if you need the speed, but other than that it isn't necessary.


Unless you want to AFK farm in lane I can't think of many uses for this that Tiger doesn't already have.

The same rotation applies both to Wingborne Storm and Wilding Claw. Though with Wingborne Storm you're going want to be more farm oriented, which is the current meta (which I will not go into).

Here is my rotation for the beginners:
1. Wolves
2. Blue
3. Wraiths
4. Wolves
5. Red
6. Gank or back.

For my experienced friends:
1. Blue
2. Their red (unless you know that their jungler is starting there, in which case follow the beginner's rotation.)
3. Gank after you have done enough of the beginner's rotation.

One more thing (you're awesome if you know this reference):
Buy a ward in the beginning if you are jungling in ranked against a notorious counterjungler such as Lee Sin.

The following can REALLY snowball a lane but it is very risky as Udyr as you have no reliable gap closing or long lasting crowd control. Try at your own discretion.

Junglers such as Lee Sin or Shyvana have very early ganks and that can really ruin a lane for you if you can't gank quick enough. This is why I propose the level two gank if you think you can pull it off. The level two gank involves getting Blazing Stampede at level two and getting red without losing too much health.

Caution:
-Might ruin your jungle.
-Might help enemy lane.
-Might give buffs to the enemy.
-Might get yelled at by team.

Despite this, the level two gank can win games if executed properly. I suggest coordinating with your team before you even hit level two. If you do decide to go for the level two gank keep a few things in mind:
-Don't just gank from the river, you can gank from a side bush or come from behind the enemy lane, without getting into tower range.
-Charge Wilding Claw by using it before Blazing Stampede and then the Wilding Claw active will activate with the Blazing Stampede passive, getting a free stun and slow.
-Take charge if the allies in your lane have little to no crowd control.

As for Wingborne Storm I am unsure how potent the level two gank is. I would recommend farming until level four for Blazing Stampede unless the enemy jungler is a serious threat or if you have a good opportunity to gank.

Team work is critical to a successful Udyr. You must coordinate with teammates to pull off successful ganks.
-Ping a target in advance
-Ping the same target again when you are ready to gank
-Initiate if your ally can't
-???
-PROFIT!

Keep in mind that you REALLY SHOULD have red buff while ganking, as it makes it much easier and can secure an early kill.

+1 if you liked.
+1 with a reason if you REALLY liked.
Downvote if you didn't like, with reasoning of course.
Ask me questions or give me suggestions please.
Please let me know if there is anything I can fix!
If this gets enough votes I will add a Phoenix section and a laning section.
Good luck with your Udyr experiences!

Changes:
10/24/12 Added a Changelog in addition to item and mastery changes for Tiger Stance jungle.

Song related: http://www.youtube.com/watch?v=ZtmuQY42kkY
Inspires me to play Udyr.