If you're reasonably familiar with CVS, you can check out a read-only working copy of the book thusly:
cvs -d :pserver:anonymous@cvs.red-bean.com:/usr/local/cvs login
(just hit return, no password is necessary)
cvs -d :pserver:anonymous@cvs.red-bean.com:/usr/local/cvs co cvsbook
(In more recent versions of CVS, the first step may be omitted.)
And if you're not familiar with CVS yet, first read the book and then check out a working copy. :-)