Yes that is how it is done. When you tighten the spokes that go to the left flange the rim moves left, tighten the right side and it moves right. A full turn on a nipple can effect a surprisingly drastic change in the rim location.

This is my favorite wheelbuilding reference article. I keep it on the screen everytime I lace a wheel just in case I have a brain fart. http://www.sheldonbrown.com/wheelbuild.html

read it all the way through if you haven't before, there's a lot of good tips and insight in there.

Just keep in mind. This is not difficult, you'll be fine.