I'd definitely buy Learn C the hard way, I've been following the book LPTHW online few weeks ago and the way you teach IMHO is the best approach so no programming folks like me can grasp the language.
Re: LCTHW, I am taking "Linux Systems Programming In C" course at ucsc extension. You are supposed to already know c before taking the course, but it has been a fun trial-by-fire to dust off ye olde c skills AND learn the intricacies of POSIX programming simultaneously.