Try looking in the Strategy subforums here - I read some good stuff. (You cna pull them up using the pull down window at the bottom of the main forum screen - they do not show up as Forum tabs unfortunately).
I am right now trying out the 'spam colony ships at the start to get as many planets as I can' strategy - but I have found that in ver 1.1 b2 the Ai is much better at working with smaller amounts of planets and is really ahead of me militarilty and technologically. Touch and go right now. (Terran, Tough level, large map).
Others have said it is best just to get a few very good planets to start and get them up to speed by buying improvements rather than buying colony ships.
In general, I buy my starport cause it's cheap, then buy a factory, build a factory, build a Tech center, build either a factory or trade center, then specialize from there. (rush buying when I can afford it) I will buy a constructor or two if I can get a resource starbase; but I hold off if not and just start building a few for later. I will rush buy my first colony ship; and don't waste time building scouts until I have several colony ships on their way. I will not build any early scouts on a tiny hull, instead when I do start making them I'll build a cargo hull with lots of engines and sensors - fewer scouts but each covers more ground.
I don't waste time researching stuff i know the AI will research - instead I research stuff I can trade that the Ai will not research often such as Sensors or hulls. This way I can stay in the tech race without spending a lot of money.
I also keep my Tax rate as high as possible - as long as I am in the lower 40's in approval my planet will grow, albeit slowly. I continually adjust my Production slider, to try and keep my factories as busy as possible. I also will adjust my research, Military and Social sliders each turm as needed early on to make sure I am not spending too much on research. Later I tend to set and forget.
I do not spend money on espionage until I am feeling like I have everything else under control.
I will build econ starbases and upgrade t hem as soon as I can afford them making sure I can cover multiple planets with one base if possible.
I only will build defensive ships at the start if I see a nearby Ai getting frisky - If I can I will not build any military in the first year at all. After that I will ramp up as needed or If I decide to get frisky....
Finally, I try to get to Sensors so I can make more survey ships to get as many anomolies as I can - they will usually pay off enough so I never have to worry much about money.
I am not the best player - or the worst - take this advice with a grain or two of Alterian salt....and good luck!