I've created a library, but now I can't find it. Under Window/etc. there is no library. How do you access it?
Did you look under File > Open Recent?
You work with a library pretty much the same way you would with an ID document file as far as opening or saving it. It has a name, and a location that you specify when you save it. You access it through the File menu, Bridge, Finder of Explorer in the same way that you access a .indd file. Like a .indb (Book) file it will open as a panel.