Hey guys, I thought I'd throw a little bit of insight into Jax. For those of you that don't remember, I used to play him quite a bit years ago and I'm pleased to see he hasn't changed THAT much since the old days.
Surprise, I'm back.
Flat AD Marks
Flat Defense Seals
Flat MR Glyphs
Flat AD Quints
I don't do scaling because I generally try to get a kill between levels 1-4 by being hyper-aggressive.
The skill sequence will almost never change.
Start with E to be able to farm and harass early on. Follow it up with Q to make escapes or to do a normal Q--->E Harass.
Max out W after your first initial 2 skills are there, follow it up by maxing Q next and E last.
With all of the new items, I'd say to start with Corruption potion now. Just be sure you optimize it by using it while you're in the battle, especially if you know your lane opponent will commit.
Bilgewater Cutlass--> Shoes --> Hextech Gunblade ---> Triforce
After Triforce, I'd recommend a GA. You're already quite a monster at this point and people will start to focus you in the battle.
GA---> Guinsoo's Rageblade ---> Situational Item.
Flash ---> Ignite
Flash ---> Teleport
Depends entirely on your play-style or your lane opponent.
When you hit 6, you'll start to be doing your major DPS. At this point, if you choose to harass, ALWAYS hit a minion twice, then jump on your lane opponent for your Grandmaster's/Thunderlord's proc.
After 2 or 3 times of this, most people will either retreat or you will be able to dive them for an easy kill.
Jax has a lot of mobility. Use it to your advantage, especially in the terrain. Hotkey your trinkets. Get used to using quick trinket jumps to avoid nasty AOEs or to escape ganks.
Learn when to commit to a fight. The more stacks that you have on you, the more likely it is that you can take on that 1v2. Use your E sparingly. It's not something that you need to use every single time it's off cooldown nor is it always something to initiate into a fight. You're vulnerable for about 10 seconds without it.
If you've stuck with me this far, thanks. This is my first guide and if your eyes aren't bleeding from the formatting, go see a doctor.
Have fun and remember that you're playing an OP champion with Jax. Don't be a **** to your teammates just because you're up 10 kills and they're dying. It's a game.