One thing that's key is to make sure you have the latest version of itunes installed as called out in this picture under STEP 1
Next up, I did experience a couple of gotcha's that I want to share:1. if you're using a bluetooth device, open up Settings >General > Bluetooth and REMOVE the device, then reconnect it. I went to answer a call after using the phone for a bit and my bluetooth shut off as I picked up the call, and it locked my screen. I had to hold the sleep/wake button and the home button until the phone restarted. Other than that...NO PROBLEMS! 2. Depending on how much memory you have in your phone 16gb or 32gb you may experience some slowness when you have a lot of apps open. This is not a problem, this is the phone telling you that its doing a lot. This is what people asked for with respect to multitasking. You wanted to be able to switch between apps and do other things. You'll be able to, it's gonna catch on real quick and soon you'll be checking mail, texting, facebooking, twittering, getting directions, buying something while listening to your favorite song play in the background. BREATHE :) It's FUN and still zippy.
And then there were 2 pages of apps...I used to have 12 pages of apps, but I found the folders and now there are just two pages of apps...or at least icons now that I know you can drag one icon onto another one and it will create a folder allowing you to drop other icons in there and little by little you'll have a clean phone which you can then add more apps to if you wish. here's the screen shot of the phone now.
Am sure there's more to share, but right now have some client projects to finish.Have fun!! Mike