How does Titanium Backup work? When will it not work?
I advise you to read thoroughly the following resources before taking any step to make changes to your OS, so you can be sure if you're doing things right with Titanium Backup:


Titanium Backup User’s Guide: The Titanium Backup manual.
Titanium Backup Technical FAQ: The most frequently asked questions.
Titanium Backup Troubleshooting: In case you have problems…
Titanium Backup Cryptography: All about encrypting and decrypting your backups.
Titanium Backup Tips &amp; Suggestions: Some useful tips.
Titanium Backup HOWTOs: This can help you get some specific jobs done.
Titanium Backup Licensing: If you have questions or problems with license keys for the Donate version or the PRO version on the Market.