I don't know if you can still get it , but I really thought this was the best C book for learning:
C from A to Z by Bryan Costales.
It takes you from the basics of if/else/select, loops, arrays, precedence, pointers, functions, types, structs/unions and so on, but not in a heavy way. I highly recommend it.
A quick search shows only 2nd hand, but that's still ok.
(this author is also THE GURU on sendmail - second to none!)