Caitlyn is a lane bully. She is very good in preseason 5 (4.21) because of her passive poke and safe damage. She is very popular in competitive play and high elo because she has no real hard counters and a good caitlyn can do well in any lane.

twitch.tv/itskittycow

During laning phase, caitlyn should zone and poke down the enemy adc. Stand near the front of your minions and get an auto attack off whenever you can. But unless it is very urgent, you should never trade one auto of harass for a minion. Caitlyn's Q does more damage if it doesnt go through minions first so keep this in mind. You have a really strong combo with your E and Q. If you E and hit the enemy, you can Q mid air, canceling the animation, and instantly Qing for some decent damage.

twitch.tv/itskittycow

Caitlyn's mid game isnt the strongest, ideally you should have a large lead from laning phase and use that to snowball into the late game. If you have an early lead, your team can start seiging towers very early.

twitch.tv/itskittycow

In the late game you want to hide behind your entire team and just poke the enemy team down. Peel is your greatest friend. If you get caught always flash over your E. Your E can get canceled by ******** everything so always flash to be safe.

twitch.tv/itskittycow

Heal and flash are really the only summoner spells for ad carrys. The heal and its move speed are a savior in lane and great for team fights. Flash is, well, flash.

twitch.tv/itskittycow

Pros:
Great poke
Strong early game
No hard counters
Cons:
Lackluster mid game
Bad duelist
needs peel to be effective in team fights

twitch.tv/itskittycow

You want to max your Q first on caitlyn just for the early game damage. You want to max your E second for the lower cooldown, because it is your escape. Your W is nice to zone your opponent in lane but it really isnt a max priority.

twitch.tv/itskittycow

Since caitlyn scales better off damage than attack speed, we start with an infinity edge. After infinity edge you really want to get a statikk shiv and some berserker greaves. Once you have these items you should be pretty strong. After these you want a bloodthirster for the life steal and shield and a phantom dancer for the extra attack speed and crit chance >70%. You can change your bloodthirster for a last whisper if the enemy team is heavy on armor. Your last item should be defensive, unless of course you're pub stomping and just want another damage item. I recommend a banshees vail because it protects you from hooks and huge burst damage mages.

twitch.tv/itskittycow