I almost always go for Ideological Thought --> Idealism first thing. Then it depends but usually Medicine, Market Structure, and Practical Steam Engine are high up on the list. With those you will get some nice growth and be able to put the education slider up to 100% if you haven't been already. Of course you don't wanna forget Biogalism for education or some of the input/output efficiency techs for the industry.
I actually really enjoy Strategic Mobility early on for the level 2 forts and +.5 recon. It can make a huge difference in the outcome of a war. Single best military tech IMO, because if used properly and early before other nations get it you can defeat nations 3-4 times your size early in the game. I totally defeated Argentina with Chile with only 4 brigades of irregular infantry using this tactic... they had 10 regiments of regulars. I didn't even mobilize. As long as you can trick them into sieging your level 2 forts, move in and siege their provinces with no forts its cakewalk. Then continuously keep a line of captured provinces between your forces and theirs, so that when they come to attack you they end up just sieging another province. The key is you are getting 4 provinces sieged for every 1 they get so eventually you can defeat just about anyone using this tactic.