I would recommend "C: A Modern Approach", 2nd ed by King (http://www.amazon.com/Programming-Modern-Approach-2nd-Editio...)
It's a hefty tome but that's not necessarily bad if you want to (re-)learn the language and the tricks in a proper way. Easily in my personal Top 5 books for C (The others are in no particular order: "Pointers on C", "Expert C Programming: Deep C Secrets", "The Standard C Library", "C Interfaces and Implementations".)