EDIT: Formatting sucks a little, had to switch it up.
Online Learning
Structure And Interpretation Of Computer Programs aka SICP - http://mitpress.mit.edu/sicp/full-text/ ... Z-H-4.html - Great introduction to Scheme and programming in general.
SICP Video Lectures - http://swiss.csail.mit.edu/classes/6.00 ... -lectures/ - Video of lectures given in 1986, they follow the first edition of SICP instead of the second edition, but they are still a great resource.
How To Design Programs - http://www.htdp.org/2003-09-26/Book/ - Another great introduction to Scheme and programming. Tries to be "nicer" to those new to either Scheme or programming.
Teach Yourself Scheme In Fixnum Days - http://www.ccs.neu.edu/home/dorai/t-y-s ... cheme.html - A great introduction to Scheme itself, including the more advanced parts (call/cc, dynamic-wind, macros).
Printed Material
SICP at Amazon - http://www.amazon.com/Structure-Interpr ... 262510871/ - SICP is available for free in the section above this one, but it never hurts to have a "dead tree" version.
The Little Schemer - http://www.amazon.com/Little-Schemer-Da ... 262560992/ - A great book that teaches Scheme in a unique way.
Essentials Of Programming Languages - http://www.amazon.com/Essentials-Progra ... 262062178/ - An advanced text using Scheme to explain the more advanced aspects of programming languages.
Reference
The Scheme Programming Language 3rd Edition - http://www.scheme.com/tspl3/ - A free online copy of the Scheme language specification.
Schemers.org - http://www.schemers.org/ - A community site for all things Scheme.
Read Scheme - http://readscheme.org/ - A large collection of Scheme related material.
Scheme Language at Wikipedia - http://en.wikipedia.org/wiki/Scheme_%28 ... anguage%29 - The Wikipedia page for Scheme.