An Introduction to Computer Science Using Scheme

[b-man]

http://gustavus.edu/+max/concrete-abstractions.html

[dragonquest]

I highly recommend this book. I used to pick this up from time to time when I didn't understand a concept from HTDP. Their explanation of the lambda as translated from Math to Programming really made me get it. One of my first joyous moments reading Scheme.

[araneae]

Or you could just take the MIT OpenCourseWare class http://ocw.mit.edu/OcwWeb/Electrical-Engineering-and-Compute... (uses Scheme also)

[b-man → araneae]

Yeah, you could go for SICP too, or as the commenter above mentioned, the HTDP.

Both HTDP and conabs inherit their methodologies from SICP. (in htdp you could even look at The Structure and Interpretation of the Computer Science Curriculum here http://www.cs.brown.edu/~sk/Publications/Papers/Published/ff...)

But it is worth to look at the same thing from different points of view. As Alan Kay says, it is worth 80 IQ points :)