I majored in journalism, and did take a sportswriting class in college. I'm as big a fan of good sportswriting as I am sport itself, and for a while I considered becoming a sportswriter. In case you're really serious, I'm going to go ahead and give as much advice as I can:
One of the things that interested me about journalism was the so-called "New Journalism," where the writing is more narrative and literary, and this style translates easily to sports. Everytime you pick up a copy of SI, you're reading New Journalism-style material. So learning a bit about the history of this style would be of some benefit to you. I imagine this is the kind of writing you'll want to do, since EVERY print sportswriter wants to do it.
But first, you need to make sure you're up on the proper journalistic style. Go to Amazon, search for "journalism," and you'll see a couple style guides listed. Picking one up from here or your local Borders should be really helpful, and you'll need to be familiar with this stuff if you want to get an internship where they'll let you write. (You also might want to pick up a copy of the AP Stylebook, the journalists' style bible, available at regular bookstores).
If you want to get an internship before college, go for it, but I'd aim low. I don't know where you're from, but don't go after the big papers. While you might make some contacts, it's more important to get the experience, and if you are able to intern at a small paper (circulation <30,000, say), you'll be more likely to have a chance at covering events on your own, and actually producing stories. This will look GREAT on a resume for j-school. But simply call up the papers in your area and find out what they might have for you. If the best you can do is as a copy editor on the sports desk, or laying out box scores, take it, whatever you can get.
College: John Updike, who wrote one of the greatest pieces of sportswriting ever about Ted Williams, majored in English at Harvard, and then wrote a famous novel, which let him write about sports. So you could do that. But I'd suggest majoring in journalism somewhere else.
There are a number of top-notch j-schools in the country, including Maryland, Missouri, Northwestern, Syracuse, Ithaca (my alma mater), USC, Columbia, Boston U, and there are plenty of others. Research them. While Steve Ruccin is a great writer, I wouldn't recommend following his example - GET INVOLVED. Experience is the best ticket to a journalism job (worked for me). Write for your school paper, and get internships over the summer, if you can. The more experience you have, the more attractive you'll be to editors who might be wary of hiring a kid straight out of college.
And above all else, FAMILIARIZE yourself with the great sportswriters of the past, including Grantland Rice, Ring Lardner, Red Smith and on up through to the present day. In fact - go out RIGHT NOW and find a copy of "The Best American Sportswriting of the Century," edited by David Halberstam (who has a few incredible baseball books, by the way). This has every piece of 20th Century sportswriting you'll ever need to read. My personal faves include the Ted Williams piece by Updike; Al Stump's profile of Ty Cobb; Mike Royko's "review" of Keith Hernandez's book; John Krakaur's Everest expedition; and Hunter Thompson's Kentucky Derby story, of course. But everything in this book is incredible.
So get to it.
Perlick is a TV sports journalist, so I'm sure he'll be able to provide some tips too.