My setup has been the following for a while with iTunes but I now use MC.
I store all my songs on a server and create 4 databases (one for each family member). I then setup each comp w/ all 4 accounts and link each account to the correct database location (fyi: I do the same thing for my docs, firefox profile, thunderbird profile, & the my music/pictures folders are the same for all 4 family members).
On my drive, I use some top level folders that may be useful for others:
Backups
Discs (CD Space Images)
Documents (4 + Shared docs)
Installers (Desktop, PocketPC)
Music (Artist > Album)
Pictures (2001, 2002, ...)
Podcasts (Audio, Video)
Profiles (Email, Internet, Music)
Video (Television, Movies, Internet, ...)
Web Site (cgi-bin, public, ...)
I have been spending many hours over the past few days and weeks carefully organizing all of my data. Every file I have is carefully inspected to ensure I am not wasting space. I finally took the time to offload a lot of archive data to DVD. I actually run off a single 500GB drive which is mirrored on two other drives for onsite/offsite backup so I need to keep my data organized and condensed so I don't run out of space.
At one point I was down to 60GB free. I went through and cleaned up/archived some stuff to DVD and got up to 120GB free.
QUESTION: I like to use the 2 complete backups solution so I have 3 total guaranteed copies of my data. I am wondering if I could get by with only 1 complete copy. If I did, I could buy another 500GB drive and have two running drives and therefore, 1 TB. I just have to keep in mind that this data cannot be lost! It has family memories, expensive software I've purchased, documents, etc. I also have around 100 DVDs of family video from my life that I keep but I only have two sets of them. The first set was made around April and the second set was created from the first around July. Only 1 DVD had a problem and I used a free trial program to ignore the error and keep copying (Cyclic rendancy error) so I ended up with a copy which seems perfectly fine. I'm thinking I'll make a 3rd set in a year or two. I don't want to make a bunch right away so close together.