I just received my vintage acoustic, and damn is it beautiful. But my one concern is the bridge. It came unattached to the body. Now I'm a noob when it comes to archtops, so I'm asking: should the bridge be glued on before stringing it, or does it simply sit on the body, with the strings holding it down?
'64 Fender Telecaster
'08 Epiphone Prophecy EM-2
'06 Epiphone Les Paul-100
'08 Squier Strat Mini
'03 Ibanez AEG10
'90 Yamaha FG730S
'31 Kay Archkraft
Yeah -- it's called a floating bridge and it'll do that. The string tension holds it to the soundboard -- don't glue it down. You may want to check your intonation to make sure it's in the right place when you put it back -- unless you can tell where it used to be. Some people have them pinned down so they don't shift on them, but it isn't necessary.

What kind of guitar is it?? Congrats on the new-to-you guitar!!!!
Yes, and the bridge must be placed carefully to give the guitar good intonation and string height.