This is my first guide, please forgive me if i make some mistakes.

I'm trying my best to give as much information as possible, i promise to update from time to time and make this a full guide for Jarvan IV!(Forgive me for my bad English)

If you would like to see what Jarvan is good against or bad against just scroll down.

I hope this guide gives u enough information to own top lane.

Pros:
Strong 1-5 level
Natural Tank (from E)
AoE hard CC
Solid Farmer
Half carry half tank
High Mobility
Zone out carries in teamfight (Video at Mid-game chapter)
Cons:
Hard countered by some champions
No sustain in lane
One of the hardest champ to master
Needs farm and kills
Needs to win lane from the start

For solo top, most of the people will see if the other guy is AD or AP, so they can decide to run armor or MR runes.
Therefore the armor pen marks scales better as the enemy has great armor and it scales better than flat AD too.
You only run flat AD for champs that has more than 2 skills that scales good with AD.

For solo top, i assume you to be playing aggressively or at least constant trade. Why??
As Jarvan is a early game champion, you always want early kills in lane, so running 21/9/0 could give you more damage while give you a little bit of defense.

I always start with boots and 4 HP pots(wait at base) as to be aggressive in lane and be able to sustain. However, for some cases I start with cloth armor with 5 hp pots. That is only when I predict I will lose level 1-3 trades. So in order to sustain longer and farm more, harassment must be taken, but no worries; you will just regenerate all the lost HP.

If you are able to kill top alone before getting any items, Congratulations, you are really Pro.

On your first time back, get 2 Doran's Blades to rape the opponent top harder. However, if their top can't kill you and you can't kill their top, buy either 2 of Heart of Gold/Philo Stone/Avarice Blade, these are gp10 items, you don't expect to kill now, you expect to farm farm farm.

Then follow my "Good Items on Jarvan" for further builds.

The trick of winning lane for Jarvan IV is ABUSING PASSIVE, some people might say it doesnt work against champions like Irelia or Renekton, but i dont fking care 'cause your E-Q combo is always burstier than your enemy, so just apply your passive on the enemy as he goes for creep farm until he's low, then E-Q+ignite or call for a dive from jungler. This will most assuredly guarantee a kill.

Question time, what if you get very low too while abusing passive?
Well you are underrated enough to catch someone off guard, you have E-Q to get away plus flash, but i suggest flash first if people try to tower dive you, so you could E-Q him under the tower or ultimate him and E-Q in a SMART direction. It is very important to win early, as J4 has amazing early game burst, a strong passive, and Q to poke.

On my 2nd or 3rd time back, I usually go gank bot and mid then do dragon, this could offer a great help to your team, as you help them win their lane by ganking and dragon for extra global gold.

Remember if there's a dragon dance(both team moving back and forth, before initiation), try not to get poked and DO NOT USE YOUR E-Q RECKLESSLY, I've seen a lot of Jarvan IVs using E-Q in the wrong time. Jarvan needs to have a clear shot for their whole team (or AD/AP carry), and E-Q them all at once. If you get aimed at the back of their team, you could juke them around, wait for your Q's cool-down and Q back to your flag.
Play Video
If you decided to stay top, keep harassing with Q and passive while farming, and call for a dive/gank if needed. Notice, DO NOT E-Q TO HARASS WHEN YOU HAVE NO WARDS. By the way, I don't recommend E-Q-AA combo here, because it may bring you an unfavorable trade at this point as your enemy is leveled up. Just farm top and harass until you can burst him down with the combos below.

Offensive:

Defensive:

Philosopher's Stone

Play Video

Build a balanced build in defense and offense. There are several items that's good on Jarvan (other chapter). Then with the balanced build, whenever there's a baron dance or dragon dance, stand in front of your team and zone their carries away from their team.

Always make sure your E-Q hits at least a carry, then focus him down first.
What your E-Q does is u zone their carries out, they cant keep fighting because you are standing in front of them while your carries are safe to fight.

If your team is behind, you should save your E-Q for whoever tries to dive into your carries. Notice, NEVER ULTIMATE AROUND YOUR TEAM, because your team will be split up like that.
Play Video

Choose the best 6 items depending on the enemy team

Offense:

Atma's Impaler**
Maw of Malmortius**
Infinity Edge
Frozen Mallet
Trinity Force**
Youmuu's Ghostblade**
Wit's End

Defensive(Armor):

Aegis of the Legion
Atma's Impaler**
Frozen Heart
Guardian Angel**
Randuin's Omen**
Wriggle's Lantern

Defensive(Magic Resist):

Aegis of the Legion
Force of Nature
Guardian Angel**
Maw of Malmortius**
Mercury's Treads**
Quicksilver Sash
Wit's End

** means those items i use the most

Q + AA(auto attack) + BACKOFF

Using this early game to harass and deny farm. It's really effective to force the enemy to use potions.

E + Q + AA(s) + BACKOFF

The basic combo of Jarvan. Be aware that you should hit your E, as E deals damage too....
But in ganks you might want to E over the enemy.

Q + Q + Q + Q + Q......

Q has short CD and deals decent damage, 3Qs should be able to take someone down to 60% or below, which is div-able with jungler.

ALL IN: R + E + Q + W + IGNITE

WTF IM GOING TO KILL THIS GUY!!! R FIRST BECAUSE I WANT HIM TO WASTE FLASH BEFORE HE USE IT TO FLASH TO GET TO TOWER AHAHAHAHA

FLASH / E-Q + R

If someone's flash is down, and you wanna secure kill, do this. Care for Champs like fizz, Shen, Ezreal etc. they can dash out with basic ability.

Why Back Off?

That's because you want a safe trade, you want to deal damage to your enemy while you don't have to take any I suppose? Moreover, If you chase after you use your combo, you might scare him off. If you don't chase, people might think "Ouch, lets farm one or two waves then recall", there's a CHANCE that your enemy doesn't go back immediately.

-Jarvan IV needs to win early
-Use E-Q to hit as many as possilbe
-Dont spam W it wastes mana
-Passive is so stong
-Smart cast works better, like WAYYYY better
-Be a Hero and stand in front of your team
-Always build a little bit tanky
-Close your R when some of your teammates are going to die
-E-Q can be used to escape and to chase

Rating from 1-10, 10 is the hardest to play against while 1 is the easiest

Vladimir 2/10

This lane should be really comfortable for Jarvan, get to lvl2 and E-Q when vlad wants to last hit, it should be able to burst vlad under 60%. Another combo should be able to zone vlad out of exp range, then freeze the lane near your tower and last hit.

Kayle 5/10

This is kinda hard if kayle can snowball Jarvan, it really depends on the early kills. What i'd do is bait kayle's Q walk back for a sec then E-Q her back. If she snowballed, try to make kayle push with E and call for a gank.

Jax 8/10 Play Video This lane requires Jarvan to outplay the jax like he's a noob, the only chance for Jarvan to kill him is lvl 1-5, after that, Jax's R passive will burst Jarvan pretty badly. The trick to win early is bait Jax's E and make him stand around ur minions and fight u, so he takes alot of minions damage. Even if u kill him or not, just try to outfarm him as ur main objective.
Irelia 7/10

This is a skill-based lane, but i think J4 has a little bit of an advantage early on as irelia's w doesnt do much damage at rank 1. Try passive-Q combo to poke her down by a little first then go all in. Later on, if either one wants to kill the other, they have to poke really really hard to do so. Equation: Try for early kills, no kills then keep farming zZz

Wukong 7/10

Another skill-based lane, both champs can deals same amount of damage with E-Q. As Jarvan u shouldn't fight when wukong has E buff(Attack speed buff), then u E-Q him once his combo is on cd. Actually i wonder what would happen if one of them buy thornmail?

Olaf 8/10

Olaf's E is true damage and doesn't cost mana wtf... Try to bait him to E u around ur minions, then E-Q him IMMEDIATELY so ur minions will focus him. There's nothing much J4 could do, just outfarm him and be a better carry diver than Olaf, u have AoE knock up, u should carry ur team better :)

Rumble 4/10

Rumble's Q deals tons of damage right phreak? Hmm, maybe we should let rumble push with Q and once his Q is almost down i would love to knock him on and give him a hug and back off. Wow Rumble has no sustain and constant Q pushed the lane, should i freeze my lane near my tower? sure why not. He pushed my lane so i get to 6 quicker, its time to burst him before he hits 6.

Gangplank 5/10

If GP likes to Q since lvl 1, he runs out of mana soon, and he'll overextend all the time, gank him. After lvl 6, J4 can always E-Q-AA, run out and take only one shot from GP, just harass harass and E-Q-Ignite-R.

Teemo 3/10

Hmm... The only difficulties Jarvan will find is Teemo's ranged harass, avoid level 1 fights by NOT FARMING, once the waves are pushed to you. Two combos of E-Q-AA-Backoff will burst Teemo down. Missing Combo will result in losing lane.

UPDATE SOON

There's nothing much for me to say, most of the points are listed on my Quick Tips chapter, I truly hope you find something out of this guide, Please comment and vote up.

This is my first ranked pentakill, i put it up here just for fun xD
It shows the job of AD Bruiser, aim AD Carry first every fight then kill
the rest of their team one by one Play Video

!Thank You for reading!