Several books for learning Common Lisp are online or for download:
* Peter Seibel, Practical Common Lisp, http://www.gigamonkeys.com/book/
* Common Lisp: A Gentle Introduction to Symbolic Computation, http://www.cs.cmu.edu/~dst/LispBook/
* On Lisp http://www.paulgraham.com/onlisp.html
It's just that these books are 'old'. Common Lisp is 30 now. But since the core language does not change much, the old books are still fine. They may smell a bit.