I am a novice iOS user and have an iPhone 4 with iOS 5.0.1 and baseband 1.59.00 and till last 2 months I was using it unlocked using ultrasn0w. I got the phone this way only when I bought from eBay. Two months back I applied for an unlock from AT&T and got it. After I connected my phone to iTunes I got the message that phone has en unlocked. To verify I booted my phone untethered (since my jailbreak is tethered) and verified that phone is unlocked but as expected I got single bar which I read on Internet that it is expected because of the firmware baseband mismatch. Long story short, want to now upgrade the iOS version to 5.1.1 but want to ensure that I do not loose any of my contacts, pics or the apps. How do I do the entire process ? I have never updated my iOS version before. Also how can I backup my jailbreak apps ?