Hi,This is my first build. So please cut me some slack. Now lets get started.
Jax, Grandmaster at Arms. A lot of people will say jax is overpowered, now this can be true but it can also be wrong. you need to know how to use him. Continue on to learn more :)

I use Dodge quints because it will help a lot with Jax's Counter Strike and then attack speed marks and Seals to speed up the passive effect of Relentless Assault . If u notice i use Magic Resist Glyphs because jax is squishy beginning to mid game.

I was a bit upset went i found out that they removed the dodge masteries from the defense section. Getting Hardiness and Resistance will help you stay in lane for a bit longer then you normally would be able to. You may notice that i don't take Vampirism but i have a Bloodthirster in the item portion, this is because personally i would rather take the 3 points that i could of used in Vampirism in something like Havoc or Sunder

I start i with a Doran's Shield because Jax is pretty squishy mid game. Depending on if u get fed before u B for the first time or not you can either get Boots to build into Ninja Tabi or just go straight ahead and buy Ninja Tabi if u have enough gold, but remember if u do not get the Ninja Tabi with Jax lets just say you wont do the best. Now it bugs the HELL out of me when i see a jax without a Guinsoo's Rageblade it was practically made for him, it basically doubles the effect of Relentless Assault . With the Hextech Gunblade it gives you a great amount of ability power with a decent amount of attack damage, but with the recent nerfes they made the spell vamp a passive so u can no longer stack Gunblades for more spell vamp. With the Active on the Hextech Gunblade i don't really use it a lot of the times it forget that its there i think its kind of useless but if you would like to use it go ahead it would be my pleasure. With the Lich Bane it was kind of another item that is just made for jax if you use Empower it will activate the passive of Lich Bane and will bring MASSIVE damage to you enemies. Now if you have reached this point in the game a Black Cleaver is a good item to get. The fact that it just shreds enemy armor is awesome, i know that when ever someone gets a Black Cleaver against me it really pisses me off because of how great of an item it is. Black Cleaver is a good item to get with Jax because of the attack speed and of course the passive. A lot of times you the game will be over by the time u can buy Bloodthirster but if you are able to get it, it will help MASSIVLEY it gives a great amount attack damage and the lifesteal is just phenomenal.

With the updates of all of the summoner spells i am very pleased but my all time favorite spell will always be Ignite

I use Exhaust and Ignite they are a very good duo. Exhaust is very useful to stop a fleeing foe, or use it on someone in the middle of a 1v1 to greatly lower there attack damage for a limited amount of time. If you dont like to use Exhaust you can use Heal instead but i greatly recommend the use of Ignite.

COUNTER STRIKE: this ability is what makes you a MACHINE. ALWAYS AND I MEEN ALWAYS BE READY TO PRESS E ( Counter Strike ). I usualy spam my E Counter Strike just so i can get the stun off as much as i can. Counter strike has saved me in many occasions, i have gotten countless amounts of Triple kills thanks to Counter Strike :D

PLUS : This will be you main combo lvl 2 onward. Just use Empower Then leap to someone and you have an empowered leap. And since since Leap Strike isn't an auto attack it resets your auto attack timer giving you a free hit so if u think about it your getting 3 hits with the press of W,Q and a right click!

PROS:
+Great Harasser
+Great Pusher
+If fed he will DESTROY

CONS:
-Squisy early-mid game.
-Not invincible :(
-Not as easy to play with as u may think

Early Game: Start out with your Doran's Shield. try not to get to aggressive, once you hit level 2 you can start doing your Leap-Empower combo (As seen in 'Leap+Empower' Chapter). By the time you B for the first time , Hopefully its not because you almost died, you should be able to buy Ninja Tabi or Boots to build into the Ninja Tabi. Just keep last hitting minions/Farming so you can keep up that gold supply!

Mid Game: By this time you should have your Guinsoo's Rageblade and be working on getting that Hextech Gunblade . Remember your still a bit more squishy but you be able to 1v1 someone as long as they dont have a stun like yours :P. DONT INITIATE, Do not initiate in team fights just because you seem so bad *** it does not mean you can tank like a Rammus or Alistar , just let the tank initiate and then come in slamming on the squishy little carry. Once you get your Gunblade, honestly you could take on 2 people at once and still get away with 2/3 or 1/2 HP. Just make sure the 2 people you are attempting to kill are not more powerful then you! And its always good to farm on minions when ever you can, use your ults passive to you advantage.

Late Game: At this point you should have your Hextech Gunblade and maybe if you have been racking up on kills you might have Black Cleaver. Start working on your Bloodthirster once you get that you be practically invincible but remember you can still die! A lot of times i never get to get my Bloodthirster by the time im working on it we have already won, haha. I hope by this time your still using that Leap-Empower combo.

If you have gotten to this point in the build...THANK YOU VERY MUCH. I put a lot of time and thought into my first build but i had a lot of fun!! I will be making more builds for my favorite champions! I will learn how to add screen shots and a lot more to my build so please comment, vote and please have fun in the League of Legends