nandroid backup

[DaEXfactoR]

I am not really new to rooting and flashing ROM's. However, I do have a question about nandroid backups. When I boot into recovery using Amon Ra's recovery method to do a nandroid backup, I am unsure what to back up. I usually just back up everything for safe measure. My confusion stems from the fact that in Amon Ra's recovery there are some objects already selected....,boot,system and data. I s this all I need to back up or should I continue to back up everything?
Thanks

 

[eldub1]

Backup the entire rom.

 

[SmokeCrawler]

The 3 pre-selected plus wimax are the only ones I use. Never had any problems when reinstalling. All info is there plus I save space and time when backing up and restoring.