As said above, expansion is the key. I believe someone on the forums once said that you should colonize like mold.
When I first start a game, the first thing that I build is about five to ten colony ships, with a frigate or two thrown in there somewhere. Make sure taht you are also building a couple of research facilities on each new planet to ebsure that you have ample supplies of research points. Another thing that I have heard on the forums is that everyone has their own method of research. Paly the game a few times and experiment with the different tech trees. Also, try playing a game with full research to help figure out what tech treed lead where.