A small Guide to Common Lisp for new and old Lispers.
This guide is at its core an abstract of the book "Practical Common Lisp" written by Peter Seibel. Therefore it is recommended (if you are new) that you read it in the first place. This document should serve as a quick-look-up for the things you have already learned (altough you could learn from it too).
Additionally many quite helpful things which are not described in Peter Seibel's book are complemented with describing external libraries.
This guide features also a Common Lisp application. This should help jumping in full Lisp action instantly. Furthermore it should give some ideas on how you can structure and organize your code.