I've tried a few different books, including Land of Lisp, PCL, SICP, Chassel's Introduction to Emacs Lisp, but what I'd recommend head over shoulders above them all is buying a copy of Touretzky's Common Lisp: A Gentle introduction to Symbolic Computation. It's wonderfully thought through, really helped me finally grok elementary stuff like what a cons cell is, exactly how apostrophes function, what asymbol is, and a lot more. It's not meant to be comprehensive, it completely leaves aside CLOS, but it's left me with a damn solid foundation for working with Lisp.