Are you new to writing? Did you see the Twitterverse all-a-twitter about this National Novel Writing Month? Yes?
Then boy do I have some advice for you! First off: don't give up! By the time you reach November 20th, chances are life will bog you down with many other projects that have to be completed. That may or may not get in the way of reaching the magical 50k mark. If that happens, stick with it, anyway. Take more time to finish that first draft. Nothing is more satisfying.
Second: DON'T send your work out to agents. This is an absolute No-No! Why? Because once you reach "The End," it's time to revise and edit. Revise and EDIT! It's something all of us have to do.
Third: Chances are, 50k won't be long enough. Unless you're writing for readers who are 13 and younger. It's a simple fact (but there are ALWAYS exceptions) that shorter books have less things that happen in them. Young Adult and Adult readers typically want more intricate plots. Therefore, those books sell better. Therefore, agents and publishers are more willing to look at books with a higher word-count. So if you reach 50k and the book isn't "done" yet, keep writing!
Fourth: Writing can be fun, but it is work. Expect to work VERY hard at it.
Fifth: Have high expectations, but be as realistic as possible. If this is your first foray into the writing world, it's important to know that it'll most likely be at least five years before you get an agent. Again, there are exceptions, but most of the people I know who are published all worked at minimum a half-decade before they took the next step toward professional authorship. Don't get discouraged. If this is what you want to do, stick it out. I've been doing this for nearly 14 years, and I'm still working on getting an agent.
Sixth: Let's say you get done revising and editing. You're sending out to agents and publishers, and they all turn you down. Not a happy thought, but it happens more often than not. Be VERY careful before you go to a local printer to self-publish. Don't just throw it out there. If no one is purchasing it inside the industry, there may be a very good reason for that. You should be getting advice from critique groups while you edit and revise. Before you go to the self-publish route, send your book back to them. Get more beta readers to look through it. And then go to as many industry insider blogs as you can and research what it takes to be successful at self-publication. DON'T listen to the places that want to sell you self-pub services. They'll either be limited with info, or they'll put dollar-signs in your eyes when it's really going to cost you more money than you can afford could tank your career before it starts. So be careful, but DON'T throw it away as an option.
Seventh, and I can't stress this enough: KEEP WRITING! You hit "The End," you finish rewrites, revisions, and edits. WHILE you're querying, start a new book. Seriously. RIGHT AWAY!
Eighth and final point: Be prepared (and don't be afraid) to throw that first book away. You do your ABSOLUTE best with that first project, but for some reason, you can't get it out into the world. You don't want to put the effort into self-publishing. But this is your baby! The hardest lesson I've ever learned is to simply GET OVER IT. I did it with four books already, and the most recent one, the best book I'd written up to that point, wasn't getting anyone's attention. So I wrote another book. Edited it, got it critiqued, and then started sending it out. And then I went BACK to that book. It was AWFUL. So I threw it out. I didn't realize why it bothered me until I wrote another book. And now I know what I need to do to make that story-world into a delightful story.
This book is not your baby. It's the first birdhouse you ever built in shop-class. Chances are, it functions as a book, looks like a book, but if no one wants to nest in it, let it go. Try again. And learn from that first attempt.
And have FUN!