my documented steps from Apple
Move iTunes folder under the mymusic folder to user/%username%/music/iTunes
You may need to manually delete sentinel.exe first (it's hidden), to do that cd /users/%username%/music iTunes
Rm <filename>
Copy c:\documents and settings\%username%\application data\apple computer\mobilesync\. ( copy entire backup folder)
Put it in user/%username%/library/application support/mobilesync/