Edit: lol, Just noticed OP's date. Oh well.
Here's some general advice.
1. Write till you finish your first draft. Set a realistic word count goal for every week and finish it. Write at your own pace, but keep writing.
2. Don't worry
so much about cliches, grammar, whether or not it makes any sense. Focus on getting the words down.
3. Let it sit for a while until you can look at it again with fresh eyes, then edit or rewrite depending on its needs. Repeat as necessary. Do not dare send off a first draft to an agent or publisher, expecting it to be accepted.
4. Make sure you keep in mind your genre word counts when revising your manuscript. For instance, publishers don't like seeing anything above 120k for an epic fantasy. Yes, yes, many epic fantasies break that, but it's better to stick with the rules until you understand how to break them.
5. Once you no longer see any problems with your work, it might be wise to get a few beta readers. You can find them at the Absolutewrite forums posted above.
Things to keep in mind.
1. If you are going the traditional commercial publishing route, then do not post any of your work online. Sure, you can probably get away with a chapter, but I simply wouldn't do it. That first chapter would be considered published, so if you posted the whole book, then you just published your work. Why would any commercial publisher want to publish something you can get for free or elsewhere?
2. Get an agent. This way you don't have to worry about Publisher's slushpiles and submitting rules.
AgentQuery :: Find the Agent Who Will Find You a Publisher and
http://querytracker.net/ are good places to start.
3. Stay away from Publish America.
4. Don't worry about copyright. The moment you put the words on paper, it all belongs to you.
Self-Publishing:
1. If you've been denied for a while, then this might be the route to go, at least for one of your manuscripts. Don't expect to sell more than 100 though and don't expect for any publisher to touch your work if it's already been published (whether by your or publisher).
2. It's benefits are mainly for already established authors, who have a fanbase that will stick with them.
3. If you want to simply get your book out there, then I would still try traditional publishing first, and only self-publish once I've exhausted every single agent in my genre. You have nothing to lose.
Traditional publishing:
1. Expect around a 10k advance (money the publisher gives you up front) for one book in a popular genre. Of course this works out in different ways. If you write a trilogy for instance, you may get a 30k advance. Or you may get 6k. It depends on how big the publisher is, and how much they like your book, along with other factors.
And that doesn't take into account royalties, which is your percentage of books sold. But before that, you have to earn out your advance (as in, if you get a 10k advance, you have to earn that back from the books sold). I'm pretty sure most authors don't earn back their advance, but I may be wrong.
Of course you won't know what your advance will be until you're offered one.
2. Get an agent. A lot of publishers, when submitting directly to them, require that you don't submit to anyone else. An agent can bypass that. Basically, having an agent doesn't mean your work will be accepted by a publisher, but it definitely increases the odds.
3. Don't pay your agent anything. Money flows to the writer.
4. By going the traditional publishing route, your book will end up in stores such as B&N, Walmart, etc. And that is still where the majority of books sold comes from.
Good luck. Writing is hard. Getting published is hard. But if you understand that, then you're better off than most who finish that first draft and think it's the next Harry Potter.
Oh, and one last thing. A good book on writing, my fav at least, is Self-Editing for Fiction Writers. After you finish your first draft, get it, devour, apply.