[arvid]

I would suggest The Little Schemer to understand the concepts of Lisp/Scheme. I would read and digest this before any other lisp book. The book appears to be an easy read but it is not. Practical Common Lisp lives up to its name and has some very good examples/projects intermixed with lessons. Be prepared to spend a lot of time manipulating, breaking down and refactoring code (for macros use macroexpand-1). This is exactly what you need to do when you get that lost feeling. The best thing about lisp/scheme is that the interpreter is always available to you to test and environments like slime or allegro IDE which allow interaction between the editor and interpreter. Also checkout lispcast (http://www.lispcast.com/)