This is my Jarvan build. This guy is great in a solo lane. By level 6 you are guaranteed a kill.

Pros:
-You have a big *** spear.
-You do insane damage with only 1 damage item.
-You're really tanky.
-Your Ulti traps people in a freaking crater.
-AOE slow.
-Demacian Standard can be used as a secondary ward.
-Demacian Standard is a group steroid for you and your team, great for taking down towers.
-Line nuke with long rage, really good for poking.
-Awesome at farming.

Cons:
-Once you're out of mana, you're pretty screwed when it comes to running away.
-Big target, easily focused.

21/9/0

Focusing on damage, and some survivability.

Summoner spells:

Flash/Ignite: Escaping/ Guaranteeing kills.

Other choices: (The recipe for choosing a summoner spell is to have at least one Utility/survivability spell)

Exhaust/Ignite.
Flash/Ghost.
Ghost/Ignite.

Attack speed marks
Health per level seals OR Armor seals.
Magic resist glyphs OR Cooldown per level glyphs.
Movement speed quints OR Armor pen OR Flat health.

This all depends on personal preference. I find the movement speed quints help with chasing and escaping. Magic resist helps with survivability vs casters.

Cloth Armor, 3 health pots and a mana pot.
Farm until you can get wriggles and level 1 boots if possible.
Heart of gold for early survivability.
Build Madreds bloodrazor.
Situational tank items:
Atma's Impaler

AD heavy team:
Sunfire/Randuins (AOE damage/secondary AOE slow)
Thornmail (Self-explanatory)
Frozen Heart (Lowers attack speed, armor, mana, Cooldown reduction)

AP heavy team:
Banshee's veil
Warmogs (Consider just build more HP as a counter to casters.)
Frozen Mallet


OTHER good items:
Shurelya's reverie. Cooldown reduction, AOE runspeed steroid. (Good for really annoyingly fast teams)
Infinity Edge. (only if youre doing well)
Black cleaver.

I WILL add more, just wanted to get this build out there.