lulu.com has a self publishing service and they can send out your book to amazon and a few other booksellers. It's about $60 to do. The only thing is, there are no editors there for you, so you have to do all of that work yourself. If you want to get published by an actual company, go to your library, find books of the same genre and find their publishers. Send them a query. Only if they are interested in your query should you send them a manuscript. Act as if they are the only publisher in the world (only submit to maybe 3 publishers at a time but dont let them know!) There is a lot of info and samples of queries and manuscript formats on about.com
your manuscript is just your book, set in the proper format (look here: [link]) those are the guidelines as well. If you have any guidelines for them, you do not mention it. it can make them not want to publish it if you throw that at them in advance. If they want it, they will contact you and you can give them your guidelines then. I'm pretty sure it's the same thing all over the world.