We call them "charity shops" in the UK, because they are owned by various of the large charities. Some of them also sell things like Fair Trade items too if they involved in overseas aid.

They're great for books, and I found them very handy for temporary clothes when I was losing weight. Can find some very nice stuff in my local one. Designer gear, because I live in rather an affluent area where people will donate things just because they are soooo last season. :D

A couple of days ago in there I found a signed framed print by a local artist that my dad likes, so that's his birthday present for this year sorted!