Where can you send stories to have them considered for publication? Most comics have the names of the editors within the credits and a website address - try looking it up to see if they have info on their site about submissons.
You should buy the 'Writers and Artists Yearbook', its always got a bright red cover, and all the major bookshops stock it. Good luck, because I believe the sector your interested in is one of the toughest to get started in.