Hot to Specify Squeeze?

[James Van Scoy <iowaboy@comcast.net>]

OK, my first attempt to create a live cd was successful. I ended up with 
a basic Lenny live cd that boots to a command line.

BUT, I just can't find out how to make the live cd for Squeeze (or Sid). 
What file do I edit to specify the dist that I want to use?

I know that for my existing Debian installation, the specifications for 
the package sources to use are in /etc/apt/sources.list. Where is this 
information for building a live cd?

Thanks, Jim