iOS 5 'home sharing' feature missing?
On the computer


Open iTunes
Turn on Home Sharing in the Advanced menu
Keep iTunes running


On the iDevice


Open Preferences
Open Music Preferences
Enter same AppleID for Home Sharing as in iTunes (note, you may have to re-enter the account if it appears already to be there. This both verifies the stored password is correct and re-registers the iOS device with your account's Home Sharing)




To Use


Start the Music app in the iPad
Tap on 'More' at the bottom right





Tap on 'Shared' to see a list of shares music libraries