I am a bit out of date on this, but from what I remember, there are about a thousand questions, in something like five different areas such as "weight and balance." So, you get roughly 200 questions per area.
Thanks to the US Freedom of Information Act (FOIA), you can get all the current, actual FAA written test questions, but of course you will not know which of those you will get on your written test!
I had some time on my hands, thanks to getting my ass fired the second time running, so that I sat down with a Jeppesen programmed learning course for the ATP that I got in exchange for overhauling a "stovebolt six" engine from a fellow pilot's Chevy; a big book of questions and answers: actual FAA questions with answers from a commercial provider; a current copy of the FAR/AIM (Federal Aviation Regulations/Aviation Information Manual); a simple, non-programmable electronic calculator; and a CR-3 mechanical calculator. After a week I went in and passed the test by a comfortable margin.
It quickly became clear that there were only so many different ways you might be asked about specific topics: not so very many as all that. For weight and balance, for instance, you might have to either shift load between two compartments, or add some load, or drop some load.
Two different questions might both require shifting some load between fore and aft compartments, when only the numbers differed; it was the same basic problem that required the same basic method to work it. This is not rocket science.
I used a combination of learning the questions, just recognizing the particular question and memorizing its particular answer, but more importantly, learning how to work the problems posed by the questions. After all, there's nothing to stop the FAA from putting some brand-new questions out just after you have memorized all their old ones. It's a constant cat-and-mouse game, I suppose.
Although you might never need to know how many flight attendants with how many megaphones are required on an airliner with X number of seats, it's all stuff you really are required to know in order to hold the license, and much of it is very useful to know.