If you know of a frequently asked question and know the answer, the easiest thing to do is use the "Contact Curtis" menu item on the menu in backupcentral.com to send it to Curtis. He'll create the FAQ entry for you and let you put your answer in there. (If you want to be a frequent contributor, then let him know that, and he'll give you more detailed instructions.)
If you know the question, but not the answer, please submit it to the Netbackup mailing list.