Start with the Encyclopedia (link above). When a link is broken, replace "galciv" with "galciv1", e.g. for the FAQ the link is http://www.galciv1.com/faq/faq.html
In the Strategies area you can find many tips. For beginners and experts.
There are also some good fan sites like NeoTech http://www.neotechgaming.com/forums/ and the Galactic Core http://www.thegalacticcore.com/ and very important for beginners is JavaScout's side http://webpages.charter.net/trevorpowdrell/index.htm .
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.