http://www.apl.jhu.edu/~hall/Lisp-Notes/Macros.html
And here an insightful statement of someone who was sceptical but became a Lisp convert:
http://www.defmacro.org/ramblings/lisp.html
Lisp is so different from all other languages that you have to use it to understand it. Just reading about it is not enough.
Note that there are many variants of Lisp. Older Lisp versions are suitable for experts only. For beginners I would recommend Scheme which is a well defined successor of Lisp. I would recommend Racket (http://racket-lang.org/) as SDK. It is suitable for beginners as well as for professional development.