Ebook: The Scheme Programming Language

Clear, to the point, nice exercises, does not put on airs. Other "Scheme books" are really about something else. Eg, SICP (Structure and Interpretation of Computer Programs - 2nd Edition (MIT Electrical Engineering and Computer Science)) is an introduction to programming, which uses the "scheme machine" as the virtual hardware, and is not really a good introduction to the language (at MIT this was done in tutorials and through self-study). Various "Schemer" books (eg, The Little Schemer - 4th Edition) are more collections of puzzles, which I, personally, find rather annoying, since the authors DO tend to put on airs -- Scheme is just a programming language, don't make it sound like you are giving the proof of the Riemann Hypothesis.