Have you read Peter Siebel's "Practical Common Lisp"? [http://www.gigamonkeys.com/book/] Its a great book to learn Lisp from IMO. The pace is just right (for me) and every chapter tackles a truly practical project. Its free online, so you don't have much to lose just to try it.

I have also heard really good things about PG's "On Lisp" [http://www.paulgraham.com/onlisp.html]. Again, its free to download, so you don't have much to lose to try it.

Hope this helps.