Hello, I'm a pretty experienced league player, but this is my first build. Now Caitlyn is definitely my favorite ranged carry. Very simple yet fun to play. I can't even count how many triples, quadras I've gotten...Oh yeah...3 pentas :) near 85% ranked wins with her. If you haven't gotten her and blowing up people from a distance is your thing, then I suggest saving for her. Anyways, here's my guide to Caitlyn.
Why do I pick these runes?
Like I said, Caitlyn is a simple champion. You're just an ad carry. So I go with the standard...
Armor pen red
flat armor seals
Armor pen quints
Just follow these masteries...again...she's simple...AD, some attack speed, some crit, some lifesteal, and some armor pen. This mastery page is just the standard ad carry. Like I said, just do it. You can look on most cait guides and find almost the exact same thing.
INCOMPLETE! i need my rest! ill finish later