Um I know a great deal about photography personally (credentials: took it for 4 years in high school and won an honorable mention in the Boston Globe Scholastic Art Contest with one of my photos), but I don't know any sites.
Ok so I looked and didn't find anything...
(I'm going to explain pretty basic because I don't know where you're starting from.)
It all depends on the camera you're using. I'm going to assume you are using some kind of SLR (Single Lens Reflex). Since all cameras are different, you will have to figure out how yours determines thye proper exposure. Newer ones will automatically adjust the apeture and/or shutter speed accordingly. Older models you may need to manually adjust those to "get a green light" or something like that. When you take the photo, make sure the shutter speed is above 30 or else you will get "camera shake" because of slight hand movement (the exception for this is if you are using a tripod).
Those are the basics of taking a photo with an SLR, if you want to know more, ask, I'll do my best to answer (as will anyone else who knows about photography).
I'm finally back for the summer, although hopefully I'll spend a little more time away from this screen.