I found that, after learning the basics of the language via K&R or a similar book, the best way to get a good understanding of C and its weird corner cases and eccentricities is just to go through the comp.lang.c FAQ page. http://c-faq.com/index.html

It's pretty comprehensive, and I found the level was pretty good for a "not total newbie, but still not familiar with the subtilties" level that can be kind of hard to find resources for.