For the beginning this and Practical Common Lisp will serve you well. Lisp isn't that difficult at the beginning, once you go past the parentheses. But soon you'll find yourself looking for an environment in which to do real stuff. Here, if the obvious choices don't suit you, I suggest trying out Clojure. It's a lisp, functional language, and it's 100% embedded in java - meaning it's probably as fast or faster then most lisps, and it has arguably the largest and best organized collection of libraries in existence.
Except the libraries aren't very Lispy. I don't think you can program Clojure without realizing that you are actually programming Java with realistic syntax. (So basically, you need to be good at Lisp and Java. As a result, I wouldn't recommend it for beginners.)
SBCL + SLIME is a nice development environment. CL is far from a perfect programming language, but you can just ignore the stuff you don't like and it comes pretty close.
