One thing I sometimes enjoy doing with programming books is just re-writing all the example code in a different language. It's a lot lazier than actually doing the exercises, but still requires you to fully understand the concepts in the example code in order to translate them.

One example: I re-implemented much of the example Haskell code from a functional data structures book in Clojure, which improved my Haskell reading, my Clojure writing, and ensured that I actually understood the algorithms.

So I heartily endorse your idea of implementing the Land of Lisp examples in Racket Scheme.

Use Land of Lisp with clisp and LispIDE. I have already posted the link elsewhere in this thread.

LispIDE already ships with CLISP and full Common Lisp documentation. If you know how to use a text editor and click on a button labeled "Run", then you can use LispIDE.

You can stop by the IRC channel #lisp on Freenode, or you can shoot me an email if you need help, or tweet me a hola. Details in my profile.