Re: Backing up phone before reset...
The first thing you need to do is make sure your phone is sync'd to your Gmail account associated with the device. This would be whichever Gmail account you logged into the device with. Go under Settings and look for something along the lines of Accounts & Sync. Makes sure under Google, you have all the important things like Contacts, Photos, etc turned on for sync.
Another place to check is under Settings/ Backup & Restore. Make sure you have this turned on also. This will backup to Google's servers under your account.
However keep in mind this won't backup things like app or game " data ". This is meant more for general settings/preferences, contacts, photos, etc.
Another option would be to look into and use whatever backup assistant app is provided by your device. Example, with Samsung its Kies. With HTC, its HTCBackup..
Text messages can be backed up by using an application like Backup & Restore in the Play Store. Its FREE and it will backup to a file that is placed on your sdcard or internal storage which you can move to computer for safe keeping. Restoring is just a reversal.. I believe they have added cloud feature too..
Good luck and let us know if you need more help.