taylor, many small publishers still deal directly with the author. Once you have a completed, polished manuscript (which never, ever happens to a first-time author on a first draft, FYI), you can figure out if you should seek a big "name brand" publisher, in which case you need an agent, or if a small publisher will do just fine.
You can find publishers in the most recent edition of Writer’s Market (US) or Writers’ & Artists’ Yearbook (UK). Each listing will indicate “agented submissions only” or not.
Remember, reputable agents charge the author NOTHING up-front. Some agents may deduct the costs of doing business (copies, mail, phone) from your first check, but nobody legitimate needs that in order to get started.
You can determine whether an agent is reputable at sites like Preditors and Editors (http://www.invirtuo.cc/prededitors/) and the AAR (http://www.aar-online.org/mc/page.do). Besides being a real agent and not a scammer preying on writers’ dreams, you also want to research an agent’s recent sales of books in your genre before sending a query letter.
Researching whether a publisher is the real deal is easier. Go to a bookstore. See any of their books? Good. No? If it’s a small press, it might still be legitimate. The biggie is that no publisher needs money from the author. None at all. Any publisher who does is cause to run the other way.
Don’t sent agents or publishers your manuscript. Send only a one page query letter and a self-addressed stamped envelope for their reply. Be up-front about the fact that you're a minor, BTW. You cannot legally enter into a contract on your own, but if a parent or guardian signs for you, it could still happen.
