I felt that my lack of experience with Lisp and Scheme was worth remedying so I picked up cheaply a used copy of Simply Scheme by Brian Harvey & Matthew Wright. It's a bit elementary but it is intended for liberal arts majors and those who find they need a bridge to SCIP.
An annoying quirk of the book is the authors’ decision to use a nonstandard library of their own creation to hide the “complexity” of Scheme. I picked up copies of simply.scm and functions.scm from ftp://anarres.cs.berkeley.edu/pub/scheme/.
Unfortunately, I'm temporarily stalled. I intended to work with SCSH, the scheme shell as a shell in Emacs, and I may, but have to work out the library dependencies and possibly language features. PLT's DrScheme might work but also has problems with the original library. This version of the library at UChicago is supposedly adapted for DrScheme but it looks like I need to remove the redefinitions of some built-in functions.