Racket in this course
To set up racket for this course, see setup
The dialect of racket used in the course text is documented on the Racket website.
There is a tutorial.
A quick tutorial, all in one file
Background on Racket and Scheme
The main site, with lots of documentation is racket-lang.org.
An accessible textbook for learning Scheme (and Racket) is How To Design Programs 2ed Videos based on the book.
A book on scheme in general and its errata
Cool hacks and advanced topics
A somewhat advanced example using racket to define parser combinators
Defining a non-lispy language in racket: brainfudge
Matthew Flatt explains syntax objects and how to implement hygenic macros