Jailbreak - how to do full restore?

[mfrench]

I have an iPhone 4 that I would like to Jailbreak. I've been reading as much as possible about Jailbreaking and have a couple of questions still.

I am currently on 4.1 firmware and I have saved my SHSH signatures using TinyUmbrella in case I need to do a firmware restore. The main concern I have is I want to understand how I would do a full restore in case the Jailbreak doesn't work out.

I understand how to restore the firmware, but how do I restore all of the apps, data, and music? iTunes would use the backup in the MobileSync\Backup directory so do I need to make a snapshot copy of that directory before I Jailbreak?

[Patato22]

Just open itunes an sync your iPhone and itunes will backup all your data..... is something when wrong an you need to restore all your data will be save but always sync before do any unlock or jailbreak

[mfrench]

Let's say I upgrade to 4.2 at some point, I then start backing up my phone in iTunes with 4.2 as the firmware on the phone. If I want to go back to 4.1, the backup in the MobileSync\Backup directory will be based on the 4.2 firmware state. Will I need to have a backup snapshot of when the phone was on 4.1 in order to do a full restore to 4.1? Or is the iTunes backup independent of firmware?

I'm mainly just trying to cover my bases so that I can always go back to a solid 4.1 backup in case anything goes haywire. My first time doing a Jailbreak so sorry for the newbie questions.

[i.Annie]

I believe you can still restore your info from 4.2.1 to 4.1. The problems that currently exist seem to be restoring with 4.x to 3.x. You should be fine to do 4.2.1 to 4.1.