Well first of all this should be in the Guides section because this is for shops where you can request pieces. I will move it though don't worry
Secondly, get yourself a nice computer program. Best one out there is Photoshop but it is pricey even though there are ways around it. If you want a simple free tool to use to try and get the hang of things you can download GIMP for free. Check that out and get familiar with the settings.
Finally once you've got yourself a program get onto deviantart and search for tutorials. Try replicating those and that way you will learn how to use the tools you have and also learn new techniques.
For now it should be enough to get you started but check the guides section as some people post tutorials there (they might be a bit too advanced for you at this time though).
i have a thing its called bamboo- its digital but it doesnt show a pic on he screen. theres a special pen that goes with it and it hooks into ur computer and i use that. look at some of the stuff i've done already....