where are iTunes playlist and other files stored on Vista?

I have iTunes 8 installed on my new Vista machine.  I also now have a seperate network storage device connected.
What I'd like to do is figure out how I can re-configure iTunes, and move any subsequent files, to my network storage drive (N:)
I'd like to know which files iTunes uses to store information that could occasionally change.  For example, the playlists or the iTunes music locations, my iPod Nano information.  I assume there are seperate files for all of these items? I have seen two instances of library files on my c:\users\... folder so I don't understand why there are two...
I have already moved my iTunes music folder to the network drive (N:\iTunes)

Here is what I need for maximum point reward:
1) tell me the names of all of the files (xml?) that iTunes keeps info in and where they would currently be located on a Vista computer.
2) also tell me what info each file contains (playlist info, music location info, etc)
3) give me good instructions on what to move/copy to my network drive so that when I use iTunes, my Nano info, playlist, library are all on the network drive.

I have a backup of my library files from my XP machine but I don't know how to use these files since the location of the music has now changed.  When I tried to use the music library file for my new setup, the playlist was there but they all had ?'s by their name (location is now different). Can I easily correct this?
As a point of reference regarding technical skills, I am highly computer technical, but inexperienced in iTunes related matters.