Max W. It gives you much needed waveclear and poke vs ranged midlaners. You absolutely need to max it so that you can shove the wave quick so that it enables you to roam. You cannot all-in a midlaner without any items before poking them with W. Just max W please.
Talon does well against mages that are skillshot reliant or mages that have weak early games. He can usually outmaneuver them and dodge their skillshots, or get straight in their face and not make them unable to abuse their range advantage. He is weak against champions that can punish him early. He can be abused very hard during levels 1 - 3. During this time, you usually want to be using your autos and an occasional W to farm if the matchup is really hard. At level 4 you can start using W to harass the enemy, since the damage you get is now worth using the mana for.
Ranged mages generally do not do well against Talon. They don't have the damage output early game to bully him during his weakest point. They usually try to auto attack harass you early. Just stick to using W to farm from 1 - 3. Then start poking them with W once you have 2 points into it. You should be able to kill them if they're like half health and you have ignite. Champs like these are Lux, Ahri, Azir. Be wary of different kits. Champions like Cass and Syndra can bully you hard from level 1 - 2 with their abilities and autos.
You usually force them to rush a Zhonya's, reducing their damage output by quite a bit, but making them really hard to kill. Go for ADC in fights if they rush zhonyas.
AD assassin matchups vary, but it's usually slightly tilted in the enemy's favor and based on skill.
Riven matchup is hard. She shields all your damage and deals way more damage than you levels 1 - 3 assuming she's competent. She goes super aggro and burns all her abilities everytime you go for CS so she's pretty easy to gank. Call your jungler when you're level 4 or even earlier if your jungler has good lockdown + damage like Rek'sai or Maokai.
Yasuo matchup is skill. If you can manage to shove minions and get lane control vs him, you can fight him in your minions easily. Just autoattack and use abilities on him. He is also insanely easy to gank.
Zed matchup is skill. He can poke harder but you can outdamage him level 4 in melee trades. He is easy to gank if he W's in, but he probably never will. In a straight up level 6 duel, save your ultimate for when he ults, and then stay invis for as long as you can so he can't get damage for his ult.
Good builds for Talon are armor penetration. Tiamat + brutalizer + last whisper is the core build. Just build for however much gold you have. Upgrade into Youmu's and Hydra later when you have gold. For last two items you can get Merc scimitar, Infinity Edge, or Bloodthirster if you're just stomping and don't care. You can get GA if you're a huge threat and get focused hard. It's all situation. Getting a crit with IE pretty much is an instakill.
good luck. too lazy to list combos.
and then 
Final build would look like 
