If you are interested in tackling a painting project in your house, then I strongly recommend that you take a look at Martha's Decorating 101: Paint tutorial for the basics.
It goes through the basics: preparing the room, choosing colors, clean-up, storing paint, how to store samples of paint in case you need to do touch-ups, etc. As you can guess, since it comes from Martha, it's quite a handy guide.
And after you've mastered painting the walls and want to try something new, the Home & Garden section of Martha Stewart .com has a variety of painting techniques to try. There are instructions and ideas for painting furniture, stairs and other household fixtures. You can also find neat ways to texture your walls to get the effect of raw silk, gingham, linen and more.