Also, it's a good idea to base your current research on what you need the most....
I tend to rush for speed.... faster you are... the more in control you are of the entire map. If it's a massive map, just get enough range until you cover your sector of space and then research life support when you wish to go farther. Shields and defenses are researched in order of threat level.... same with weapons. You don't simply research everything because you can.
Are you in peace time? Are you at war?
Lots of questions come into account when it comes to researching. It can be stifling, but you just need to set yourself on a path. I've actually turned to keeping a notepad open and typing stuff down that I know I need. It's easy to get sidetracked and forget you were working your way to something.