There are some good resources on the web, several mentioned above. Worth reading.
Then there is the really boring thing called a manual. Read it. Twidle with knobs, levers, settings, ... Then read the manual to figure out how you got it into THAT setting. Take some outdoor shots of your boring back wall with different settings and read the manual to figure out what those settings refer to. That snaggle of cable a the back of your computer is fair model for indoor testing.
Oh, and did I mention that you should read the manual? Over and over again until you know what every adjustment on your camera does. It is a real drag to have to figure that out while trying to get a back lit shot of the Loc Ness monster.