Just read On Lisp and find a primer on Scheme macros. Then if you're still interested read Let Over Lambda. Few languages do macros like lisp, so it's worth looking at the macros to understand a new concept. Besides that, though, I don't think lisp has anything world shaking.
Also if you happen to like what you see in macros, try also checking out parsing words from forth or factor.
Also if you happen to like what you see in macros, try also checking out parsing words from forth or factor.