How to save my iphone's information?

I want to change my phone's company. But the person who's changing it said that once my phone's company is changed all the information (contacts, pictures, music etc,) will end up being deleted. I want to save all my iPhone's information so they told me I should use iTunes. Or can someone please help me step by step? Thank you.

Added (1). Please I need help.

Why does my iPhone 4s rotate pictures?

Whenever I take a picture on my iPhone angled right it changes the angle to left or if I have it angled left it turns right. I don't know why it's doing this or how to fix it?

What happens if i go over 2gb at&t?

I just bought my iphone 4s with 2gb a month. I'm really nervous as to go over. I had 115mb in one day! Is it siri taking my data or what? I did download about 100mb in games on my 4g network could that be it? Does it take data for the games/apps i download if i'm not on Wi-Fi. I just want help on how to manage my data and apps and basically what happens if i go over my 2gb a month. Don't answer unless you know. I will best a answer if they help please i need help so bad.

IPhone 4s passcode not working?

The locking passcode that comes and asks for the 4 digit passcode isn't coming up anymore. I reset it and made sure it was on in the settings but it's still doing it. I turned it off and on and it did it once but then stopped. I'm really angry; I only got it yesterday.

Iphone 4s not recognised by computer (Technical challenge)

I'm literally at the end of my tether and need some help but keep going in circles on the apple website. I have a 4s and a windows 7 laptop (possibly 64bit), I have had the phone two months and up until two weeks ago all was well now when i connect my phone to my laptop nothing happens. No little windows usb noise, no acknowledgment on itunes, My usb ports are fine other usb items connect fine, the cable i'm using to connect is also my power lead and when plugged into the main it charges, whilst plugged into my pc it does not charge.
Ruling the ports and the cable out i can only presume it is either a software issue on the pc or on the phone both would be strange as i haven't changed anything and it just stopped one day. I have followed the apple advice about re-installing the driver as it did not show up in my devices under the USB tab, the tab showed USB composite device which i'm guessing was my phone as it disappears when i unplug the cable. Anyway, I followed more instructions and attempted to re-install the driver however it would think about and then give me error code 10! However when i then look on my devices "USB composite" has changed to apple mobile device but with an exclamation mark, which apple tells me this means there's an error and to re-install it however the same thing keeps happening. Someone please please help me, my life does not depend on me updating my iphone however i paid for an iphone and i've invested a good two hours going in circles here.
P.S I have done all the easy stuff which hasn't worked e.g. Turn off phone, reset pc, delete and install itunes etc…

My iphone's charger exploded and the iphone is not working?

So today i was charging my iphone 4s with it's USB but with the ipod adaptor and then it was working good for 2 days noe but then a while ago the charger exploded while my iphone was connected and then no matter what I do it doesn't work can anyone please help me I was gonna go to the shop where I bought from and see if they can do anything about but is there any hope of it working again please help me

Why won't my Nike + shoes calibrate to my iPhone 4s?

Do I need a receiver or something? It told me to walk around to activate the sensor but i walked around for a good 15 minutes and it didn't calibrate… Am i doing something wrong or is there another gadget i need?

What Are Cheap Things On Amazon And Why Are They Cheap?

On Amazon.com I've noticed that some things are sold for very cheap (like iPhone cases) but other things like clothes and shoes seem to be full price. What are categories or things that are sold very cheap on Amazon? Why are some things cheap but others full price? Also, how can some things be sold for so cheap when they retail for way more?

How to fix jailbroken iPhone 4s in recovery mode? - 1

I was trying to unjailbreak my iPhone 4S by restoring it to factory settings. Then, it said The iphone "iphone" could not be restored. An unknown error occurred (21). I then tried shift-clicking restore and chose firmware 5.1.1 (which it is on) but it comes up with the same thing. My iPhone is now stuck in the picture with the USB pointing at the itunes symbol.