Last year, me and three good old friends of mine founded a small web/mobile development team. Things are going pretty well. We're learning a lot, and new people are joining the group. Keeping knowledge always updated and in-sync is vital for us. Long emails threads are simply not the way to go for us: too dispersing and confusing, and hard to retrieve after a while.

How your team manages and organizes common knowledge? How do you collect and share useful resources (articles, links, libraries, etc) inside your team?

Update: Thanks for the feedback. More than using a wiki to share team common procedures or informations, I'd like to share external links, articles, code libraries, and be able to comment them easily within my team.
I was particularly interested in knowing if you're aware of any way/webservice to share a reading list with a team. I mean, something like Readitlater/Instapaper, but for teams, maybe with some stats available, like "# of coworkers who read it".