Hello, welcome to my guide, Jax is my top main since pre-s2
At start you have to buy potion, and trinket.
In laning phase vs ad melee try to come with e then aa with w and leap to minion with q
In laning phase vs ap caster you should harass but dont be a rambo, q w e and run
Jax is very snowball champion, while you push first turret on top you should go roam, your ganks are very easy, just press e them w and q and leap into your enemy face, if your midlaner/botlane helps you, you should get many gold from assist or frags, if you and your comp dont kill enemy go to push turret, jax is very good lane pusher with his spellblade from trinity force.
Item order - potion, phage, stinger, phage -> 3force
then if your playing aggresive go and build guinsoo its very good on jax, while you have 8 stacks on guinsoo your r trigger every 2 auto attacks.
if your losing or want to go a little bit tanky my choice is sunfire cape, then go botrk, spirit visage and randuins omen.
First max your w which resets your aa, its very good while splitpushing.
Then max e and last skill to max i e
My choice is also steraks cage, its very good in teamfights, you just leap on the adc or fed ap caster. You got a lot of damage on your face then steraks triggers making you immortal :)
Example midgame final build
ionian shoes 3force guinsoo steraks and hextech revolver for gunblade.
Thanks for reading, ik my english bad but im doing my best