Right, did all that. ;)

The last step yields:

  Reading package lists... Done
  Building dependency tree       
  Reading state information... Done
  E: You must put some 'source' URIs in your sources.list

Debian (#!) over here.

EDIT:

Even after updating my /etc/apt/sources.list, and having the build-dep step run without error, I still get that original message. :(