This might seem a ridiculous question, but can you actually write? Have you written anything that has been published?
I'd suggest that you arm yourself with the 2008 edition of the Writers & Artists Year Book (your library will have a copy if you don't want to shell out �14.99). This book will tell you everything you need to know. Try knocking out a few letters to newspapers/short stories to magazines etc and see how you get on. You could also join your local writers circle (details from your local library.)
Good luck.