New computer (used but new to me)- authorized and can view my account information but no music
I am signed in on itunes and it is authorized to my new (used) computer. However, my library of music doesn't display. Any suggestions?
Have you downloaded your past purchases onto that computer, or copied your music onto it from your backup and added it into iTunes (File > Add To Library) ? Authorising your account on the computer just means that you will be able to play your content on that computer and/or sync it to your iOS devices, but it won't put your library onto it.
Re-downloading past purchases (not available in all countries) : http://support.apple.com/kb/HT2519