PROS:
-Nice dmg
-Good Initiator
-Good Survivability if built right
-Has a good slow and shield and knock-up
-His Ultimate can be devastating and is good to stop fleeing champions


CONS
-First 5 minutes is hard
-Mana reliant early game
-Can be CC'd and his ultimate can trap him to his death (if not used properly)
-Vulnerable to CC
-His ultimate can be flashed out of

Top Choices
My number one choices for Jarvan's spells are definitely ghost and exhaust.

Exhaust is a key spell to this build for a few different reasons. One of the biggest uses is to keeping enemies from running as you dish out the big damage. Many of your kills will come from you chasing down enemies as they are running away.Exhaust is also great for one on one fights with another powerful melee character. The reduction of damage the other character has while you are duking it out will often change the battle in your favor. Finally, with the mastery points set like I've shown, you also lower the opponents armor to deal some extra damage.

Ghost-Your champion ignores unit collision and moves 27% faster for 14 seconds.
I pick this spell for the same reasons. Your chasing ability is poor so by using it you can run faster, through minions and aid your team in a fight, chase down enemy champions, defend turrets or even avoid dying.

Other Options
Ignite is damage over time spell that targets a single champion, dealing 50 damage plus 25 damage per level over 5 seconds. Ignite ignores enemy Magic Resist, and reduces healing and regeneration by 50%.
Well the description says it. It's a DoT on enemy champion which can help you to successfully score a kill when used with a skill combo. Also its effect of reducing healing and regeneration by 50% is helpful when chasing or fighting team fights. Common example is the use of it on Dr. Mundo to minimize his Sadism healing effectiveness.

Cleanse - Removes all stuns, slows, taunts, fears, snares, sleeps, silences, blinds and immobilizers and reduces the duration of newer applied ones by 65% for 3 seconds.
Yes you can choose this spell if you have a hard time escaping gangs. It's the most reliable escape mechanism because it removes all CC from your champion and reduces CC on your champions for a few seconds afterwards.

Farming

Farming is fairly easy with Jarvan. In Early Game, Jarvan like most champions would just auto-attack and last hit minions to gain gold. He deals a significant amount of damage early game and withDemacian Standard , he deals more faster (with attack speed).

When you reach level three in the game, you can start throwing yourDemacian Standard behind Caster Minions and useDragon Strike to deal extra magic damage and you should be able to damage the minions ALOT or kill them and gain lots of gold. If enemy champions are nearby, right after you transition toDragon Strike[/b, quickly tapGolden Aegis to shield you from damage and effectively slow everything around you.

This is basically his farming method the whole game.

In summary, Jarvan is a very good champion to play if your looking for someone who can dish out decent amounts of damage and tank at the same time. He is fun and has some cool effects and pleasant jokes. I am open to suggestions of improvement and please rate the guide, explain your vote and have fun!

GAME SCORES (I'll add some screenshots later)

16/3/6 (Normal Game)
7/1/9 (Normal Game)
10/2/7 (Solo Ranked)
15/5/10 (Normal Game)

Some information comes from this build: Click me