You should have some artistic skill. AKA Drawing minimum.

The quickest way would be to self-teach yourself (using books and the internet) all the pertinent programs, such as Photoshop, Illustrator, Dreamweaver, In Design, and QuarkExpress. Then grab a book on Prepress, Typography & Visual Design and review those.

Then go on sites like Craigslist and start bidding for some independent contracts for stuff like CD Covers, Tee-shirt designs, web sites, etc to build up your portfolio. Make a website posting all your work and then network for some more contracts and clients. Especially small businesses. Basically freelance part-time. Join all the relevant orgs, like AIGA etc…

The official but SLOWER plan. I’d just go to school through an accelerated 18 month program and get a degree in it, and then go through the steps from the second paragraph.

Both approaches worked for me. I self-taught myself, and then went to school after doing freelancing for a while. I was able to increase my clientele and the kind of work I could do after school. A friend of mine never went to school for it, but we break about even on the amount of business each of us brings in. He’s just as good as I am. The only koodos is that I can sometimes land larger firms because of my education. ~_

I hope that answers your question. ^_