This, the standard document itself (it's not very long, and drafts are freely available), and the C tag on stackoverflow (often contains comprehensive answers by well informed people) are my recommended resources.

http://port70.net/~nsz/c/c11/n1570.html

http://port70.net/~nsz/c/c11/n1570.pdf

http://stackoverflow.com/questions/tagged/c

A good way to casually browse SO for interesting information is filtering by questions in the last <time period> and ordering by votes.

http://stackoverflow.com/search?tab=votes&q=%5bc%5d%20is%3aq...