How to build a Facebook-like newsfeed?

I was just discussing with a friend how to build a newsfeed like Facebook, Twitter et al that (seems to) take into account what you are interested in but also what is popular among users you are connected to.

Do you know any pointers on where to start may it be books, articles, tech talks, research papers or insights (e.g. related to user experience, weighing, …).

Any pointers more than welcome.