I start by researching Planetary Weapons, Tractor Beams and Stellar Harnessing... ok, I'm full of it.
I tend to always research: Missiles, Depleted Uranium Cannons, Armor, Shields, Propulsion, Point Defense - with the 100,000 start this means I have a basic warship at my immediate command while I prepare. I then research ships up to Light Cruiser and then focus on DUC and PD, and then Armor and Shields. Then I do whatever is current for the ongoing game
Jason2