I was wondering if you could explain the process for a book to be accepted for publication. I know the agent submits it to an editor,but what happens next? if the editor loves it can they make an offer outright, or must they get approval from whomever? And what does approval entail and generally how long of a process is it?
The answer totally depends.
Depends on the type of ms, the style of publisher, the personality and position of the editor, the perceived "hotness" of the project, whether there are holes in upcoming lists that need to be filled quickly, etc etc.
BASICALLY:
Agent "pitches" project to editor. I usually do this via email or in person. I am not a phone-type person. Other agents always call. Basically, we are describing the project and saying, do you want to take a look?
Editor says "sure, sounds awesome!" or "nah, too much like something else we have, sorry."
If "sure", agent sends editor ms, usually via email.
Editor reads ms. This could take 24 hours or less (I have had offers that quickly) -- or it could take six months (I've had offers that slowly) -- or anything in between. This is totally about how urgent the editor thinks it is and how busy they are. If they feel like there is going to be competition and they really want it, they will usually jump quickly. Usually I expect to start hearing from people within a month, that seems about normal to me.
Some editors have to get permission from every single person - publicity, marketing, sales, the big bosses, the janitor practically. All of those people have to read the book (or at least a hunk of it) and approve buying it. These meetings are called "acquisitions meetings" and they take place every week, every other week, or once a month (depending on the publisher.)
Some editors don't have an acquisitions process, they have to just convince their boss (or in some cases they ARE the boss). So the process from "I love it!" to "Here's my offer" can take a day, a week, or a month.
And the rate of success at these meetings is totally variable too. If your project is strong but it looks weak compared to other things that are up for discussion, they might well pass. If the editor loves it but she can't convince her boss that it will make money, they will pass. etc etc.
Everyone's path is different. If anyone tells you 'this is how it is supposed to happen', they are bullshitting you -- the only things you can be sure of in publishing is that you can be sure of nothing, and everything takes WAY longer than you think it should. Take a yoga class.