I am sending my Iphone4S to repair. How do I backup everything from my phone ?

Plug into iTunes and back up there, or use iCloud

the faster option is to plug it with the cable and backup it through iTunes.

http://support.apple.com/kb/HT4946

This is how to back up

miami626 wrote:

I am sending my Iphone4S to repair.

Be sure to do this too...

Do I need to turn off Find My iPhone before having my device serviced?

Yes. If Find My iPhone is not turned off, technicians may not be able to perform service on your device.

If it is not too late this covers exactly your question

http://support.apple.com/kb/HT1438