I'm fairly new to this game, I'm just using this to mess around so that I can see how I should be building my Caitlyn.

Caitlyn is the only champion I really use, and I'm trying to get a feel of what works well with her and what doesn't.

I would normally go with Ghost/Blink and Cleanse/Clarity, depending on how I feel like playing.

With the mana runes clarity is only useful early game. Ghost I use at the moment as I'm only level 11, and haven't unlocked blink as of yet, but either can be useful for escaping ganks.

Boots of mobility + Ghost + Phantom Dancer gives some crazy movement speed too.

I went with Malice runes just to make sure that by late game you should be getting a crit basically every shot. (If you buy a phantom dancer instead of Last Whisper, depends what you want, really.)

The Clarity runes are there to help with a little bit of mana regen, so you can lane for longer periods.

I normally grab Meki Pendant first up, so that you have the ability to spam your Q more. I normally rush Tear asap, then buy boots before finishing off Manamune. With Manamune maxed you get approximately an extra 40-45 AD.

As I said I'm relatively new to the game. I don't expect others to use this build, I just have it here so that I can mess around with builds and I can see what I need to specialize into.