I take it you're looking for a good program to use?
Well, if you're looking to punish yourself, practice and use Microsoft Paint. It's a bitch, but it's free.
The next step up is Photoshop Elements. The newest version is about $90.00, older ones about 50 or so. It's a pretty good program with all the necessities for drawing. It's what I use for all of my drawings and I'm very happy with it.
If you're willing to pay the price, you can also purchase the full Photoshop program (the latest version being - if I'm correct - photoshop CS3). I've never had any experience with this program, but I've heard it's very good.
For about the same amount of money, you can purchase Adobe Flash. This gives you the ability to animate as well as a style of drawing the differs slightly from the Photoshop series. I've had only limited opportunities to use Flash, but it's an excellent program once you get the hang of it.
You can find all these programs (except for MSPaint - obviously - because it's installed in all Windows operating systems) for sale on the Adobe website and available for ordering in your local tech store (i.e. Best Buy).