The Development of Chez Scheme [pdf]

also, the principals of ai programming lisp book walks through implementing a scheme interpreter as well as a compiler in lisp. (it's tougher than it appears, for one thing lisp doesn't require tail call optimization, so you need to manage the stack explicitly.)

check out sicp chapter 5, online! http://mitpress.mit.edu/sicp/full-text/book/book-Z-H-30.html...

scheme is fun.

edit I've heard great things about lisp in small pieces, but i haven't read it myself.

ReadScheme (http://readscheme.org/) also has a ludicrous amount of good docs - I particularly recommend the Lambda papers, RABBIT, Orbit, and Dybvig's thesis.

There's also good Scheme-related content in Peter Norvig's _Paradigms of Artificial Intelligence Programming_ ("PAIP"), but I'd recommend it highly even if you didn't care about Scheme. Its code samples are mostly in Common Lisp (inc. a Scheme implementation), but it's an excellent book about programming, period.

That should keep you busy for a while. :)

Edit: Also check out this comment from Mahmud (http://news.ycombinator.com/item?id=835020), with lots of additional suggestions.