proper way to deal with *.deb file

[Jeffrey Holle]

In a search for rcs, all I found was rcs_5.7-15_i386.deb.
I downloaded this and found that it contained 3 files.
  1. data.tar.gz
  2. control.tar.gz
  3. debian-binary

I found what I needed in data.tar.gz, and employed tar to install it.

My question is the proper way to work with *.deb files?
Since I made no use of the other files, suspect my approach isn't proper.