Don't do it that way.
Read these. If you're going to start doing this you need to know how iTunes works. This can get messy fast.
What are the iTunes library files? - http://support.apple.com/kb/HT1660
More on iTunes library files and what they do - http://en.wikipedia.org/wiki/ITunes#Media_management
What are all those iTunes files? - http://www.macworld.com/article/139974/2009/04/itunes_files.html
You have two options.
1) Share the whole library. Disadvantages: a) Somebody makes changes you don't like then there's no way to undo it easily. b) The library file can only be open on one computer at a time.
2) Share just media. Each user has their own library file but share media files. Multiple people can run iTunes at the same time. Gets slightly tricky making sure each computer is up to date on new media added.
To do 1) you should have:
iTunes: How to move [or copy] your music [library] to a new computer [or another drive] - http://support.apple.com/kb/HT4527 - a somewhat bewildering and not always easily understandable set of options.
Quick answer if you use iTunes' default preferences settings: Copy the entire iTunes folder (and in doing so all its subfolders and files) intact to the other drive. Open iTunes and immediately hold down the Option (alt) key (shift on Windows), then guide it to the iTunes Library.itl file in the moved iTunes folder.
For the record there's this reference for iTunes 11 but it really doesn't strike me as having the specifics you need. iTunes 11 for Mac: Move your library to another computer - http://support.apple.com/kb/PH12168
To do 2 we can provide other instructions.
Finally, don't do this with Time Capsule. When your TC drive dies you lose not only your original library but the backup at the same time. Unless you have two TCs, one for a file server and the other as backup.
