10. How do I go about getting an agent? Where do I look for one?
The first piece of advice I want to give is this: finish your book first!
Now, assuming you've followed the above, finding an agent is an arduous process, but the single most important thing you're going to do as a writer (besides write the best book possible.) There are a few things you can be doing while you're writing your book, and they are --1) read books you like and keep notes of any names listed in the acknowledgements; 2) subscribe to professional magazines <(for science fiction writers, Locus Magazine/ for romance folks, Romantic Times) and check listings to see who is selling what/who. In Locus, you can easily see which agents are selling a lot and a lot of new authors -- make special note of those names; and 3) attend conventions.
In science ficiton, there are plenty of panels where you can go and listen at the feet of actual agents and ask questions about the sorts of books they're selling, etc. In SF/F, however, DO NOT harass any agents or attempt to give "elevator pitches" unless specifically asked. Romance writers have it a little easier. At the romance conventions, you can actually sign up to pitch prospective agents and there are workshops you can attend to teach you how to do so effectively. (Note: you can find a list of conventions in the professional magazines listed above. SF/F writers could attend a convention every weekend, if they had the money and the time. Romance writers, you get a couple of big ones a year -- RT Convention and RWA's convention. Probably there are others, but I have to admit knowing much less about the romance process for finding an agent.)
Once you've got your list of prospective people, I recommend checking out their web pages, if they have them, and see what Predators & Editors has to say about them. If they have a web site, be sure to take note of what kind of package they want sent, whether or not you can simultaneously submit, etc, and FOLLOW THE RULES.
I should say that I found my first agent the old fashioned way... I got a recommendation from a professional writer friend. These are hard to come by because you have to be the sort of person who can effectively schmooze (without oozing) professional authors and get them to lend their name to your cover letter.
The cover letter is probably worth a post of its own, though you can find lots of advice out there. A quick search produced this: writing tips: the cover letter/query. I'm sure there are dozens more out there.
The other piece of advice: come up with strategies to deal with rejection. It's a fact of writing life. Persistence is more important than talent.