My galpal Muushka is absolutely right.
I brought a Nikon D3100 this year. This is my first DSLR camera. I immediately signed up for a few on line classes there are tons of them. My favorite is called Digistal slr guide. The owners name is Chris ?? (can't remember his last name) here is the link
http://www.digital-slr-guide.com/dslr-lessons.html
For I think 16 bucks you sign up and get extensive explanations and homework assignments. You can save the information and go back over it whenever you want. The explanations are "keep it simple, stupid" easy. Well worth the money. I signed up early May and I'm having a great time using my camera. I signed up for his newsletter which always has good information and his site will even help you pick out some lenses and cameras. I even found a link to a site where I can rent lenses and try them out.
You learn about
exposure
shutter speed
aperature
and much more.
The site is wonderful, I go back over my lessons all the time. well worth the money.
have fun.