Start with the Encyclopedia (link above). When a link is broken, replace "galciv" with "galciv1", e.g. for the FAQ the link is Link
In the Strategies area you can find many tips. For beginners and experts.
There are also some good fan sites like NeoTech Link and the Galactic Core Link and very important for beginners is JavaScout's side Link .
For the first start: Increase the spending to 100% and choose 100% military until you got enough colony ships. Don't buy anything, it's too expensive. Adjust the tax rate to keep the moral at 100% to increase you population (doubled growth rate at 100%) at the beginning. Make sure that all your planets are building something in both categories since otherwise the money is lost.