Absolute beginners guide to c is very lightweight & accommodating http://www.amazon.co.uk/gp/aw/d/0672305100/ref=mp_s_a_1?qid=1290688733&sr=8-1
If you're going the k&r route there is the c answer book which goes with it apparently, I've not read it myself but it explains the answers to the exercise in k&r http://www.amazon.co.uk/gp/aw/d/0131096532/ref=mp_s_a_1?qid=1290688949&sr=8-1 Sevan / Venture37
