What do I build on Quinn?

Ghostblade into rapidfire is pretty good

EDIT: I did someting like this a few days ago and it didnt feel that bad http://prntscr.com/blyao3

damage

This is a guide put together by the QuinnMains subreddit. Very comprehensive and useful if you're looking for advice on Quinn: [x]

TL;DR of it though is that Youmuu's is probably the best item to rush on her, and if you're not feeling comfortable with your lane opponent you can rush Phage or Hexdrinker instead, depending on the matchup you're in (Phage for sticky melee enemies you need to kite, Hexdrinker for strong AP burst) and build Youmuu's afterwards. A Zeal item + Infinity Edge should find its way into your build at some point.