Traditional artwork, the use of pencils and charcoals and paints on paper and canvas and things of that nature, is a very difficult skill to master. You need to know what you want before you even get started and you also don't have much room for error. Digital art, on the other hand, while it's good to know what you may want to start out with, you have so much room for experimentation with colors in different layers and effects that you could completely change your mind about what your final product may be if you want to. Plus, any slip ups you make can be easily remedied by Ctrl+Z.
Even if you really like the traditional effects of using watercolors and the sort of graininess you can get from charcoals or the smudges of pastels and paints, many of these effects can be mimicked in digital art programs like Corel Painter and Adobe Photoshop, only you have the lovely convenience of being able to undo a bad stroke.
But of course, such programs can be really expensive, especially professional level Photoshops. Corel Painter 11's full package is $299, and the best Photoshop you can get to date, Photoshop CS5, is at a whopping $699. There are cheaper, smaller packages with plenty of tools you can use to achieve nearly the same effects, like with Photoshop Elements 9, which is mainly for editing photos.
Recently, however, DeviantART released a free online program called DA Muro for its members to use that has both basic and pro capabilities. If you ever wanted to try digital painting, now's the time. Membership with DeviantART is free, but you can subscribe with them for a fee if you don't want to see the advertisements and have a few extra features to display your profile page and gallery. Plus, you can share all of your artworks, whether they be traditional art, digital art, sculpture, textiles, photography, anything! And you can get feedback from fellow deviants about your works with comments and favorites. It's super fun, I promise.
If you are interested in digital painting at all, then I highly recommend purchasing a tablet. Wacom makes great tablets, and for those who are just starting out, you can get a Wacom Bamboo tablet with pen touch...
...for $69 and it even comes with Corel Painter Essentials 4, a sort of easier, watered-down version of Corel Painter 11 that still has plenty of features to do what you need to.