Would itunes save the files on the iphone when you restore it?

Hello all, I've done some research online and couldn't find a more specific answer. Earlier today, I upgraded my iPhone's software and during the upgrade I lost all my data stored on my phone. Through searching online I found that my back up files are...

my iphone is either a 3gs or 3g not sure :) its been jailbroken + unlocked but it wont show any wifi signals , any helo apreciated its on 4.2.1 and someone told me if i use itunes to restore my iphone it should hopefuly fix my wifi problem , but ill...

i was trying to download all my pictures off my phone, i was on itunes it told me to update, i do not have my phone backed up so i decided to so i can save everything because im switching to a new phone. it updated then my phone shut off then itunes...

The reason I ask this question is because I have a bricked iPhone 4 with iOS 4.2.10. I have tried many times to get it out of that to no avail. I am currently downloading the iOS5 for the update. I have had my iPhone on DFU mode but the download seems...

and if i 'back up' will it save everything?? like including contacts, messages, pics, videos, music, apps, etc.?

I have an old MacBook (purchased in 2007) running OS X 10.4.11. I have a new Verizon iPhone running 4.2.10. Is there a way I can share/send a PDF from my MacBook to my iPhone without Internet? My MacBook's iTunes (9.2.1, which I think is up-to-date)...

Yesterday, I was updating to a new version of iTunes with my iPhone connected to the computer. Then, I forgot about it and accidentally unplugged my iPhone, and it hadn't finished updating yet. So that sent my iPhone into recovery mode, which is when...

Yes, I do have app sync. I have synced my iPhone to iTunes and my games to the the app section of iTunes. If I restore my iPhone, I "unjailbreak" it. Will i still have the apps from installous that synced to tunes via appsync? Or do I have...