Basically, for Talon you're going to want to get as much AD as possible. Don't worry about Attack Speed, Crit Chance, any of that. You are an AD burst assassin, and as such, you rely on your spells more so than champions like Tryndamere or Master Yi, which are basically auto attack champions. Unlike them, all you need to worry about is AD for your spells to scale off of. You wont be doing much auto attacking, mainly jumping in and pulling off your combo and getting that easy penta-kill (no really).

The items are petty self-explanatory. Maximize your AD while having some defense incase the enemy targets you. You'll definitely need Frozen Mallet as soon as possible so that you can utilize your 10% damage increase passive.

Early Game

You are weak early game, so don't attempt to pull off the double kill before minions spawn or you'll just give up first blood and end up looking like a fool. Max out your W first so you can farm creeps and harass easily.

Mid Game

By mid game when your champions start leaving their lanes, you should be looking around the map for opportunities to gank. If you get ganked yourself, remember that Talon has a pretty solid escape mechanic (his ultimate). Also, if you don't have your frozen mallet yet, remember to always have red buff on so that your passive always procs.

Late Game

This is where you shine. Your enemies will be too afraid to even go into their own jungle in fear that they might run across you. You will own anyone 1v1, but you will also dominate in team fights. Jump in, pull off your combo and use your ultimate. During the time your invisible, you can let your Q recharge to continue the rampage.

So overall, Talon is my new favorite champion, he is a lot of fun to play and he is also incredibly powerful in the right hands. Good luck & have fun!