Hi,
I really need some help, and I'm relatively dumb when it comes to technology so please be gentle and if you can help I might need spoonfeeding!!
My Samsung Galaxy SII seems to have died!!

Before yesterday my phone was perfect with no issues. Then yesterday, a message came through from a friend and when I swept the screen to read it and the phone started vibrating (not set to vibrate ever, no haptic feedback setting etc, so a very alien thing for it to so) in continuous bursts. The screen was switching between an app update, the home screen (a live wallpaper) and a blank screen in micro-second switches. Then the phone would reboot and the cycle would start again.
The phone started to get very hot (I assume because of the continuous vibrating) and it wouldn't switch off so I did the only thing I could think of and pulled the battery out. When it had cooled down I swicthed it on and the same thing happened again. It has done this ever since and other than about 5 seconds when the phone has just been switched on the phone is completely unusable.
I have phoned O2 as it is only 2 months old and they have told me to take it into a store and return it to be serviced and/or replaced. My only issue is that my contacts are all saved to the phone and have not been backed-up recently and I have some recent pictures saved to the phone memory so if I can salvage these then it's really not that big an issue but I don't know how to attempt this. I have tried to connect to Kies to download pictures / back-up my contacts but because it keeps rebooting it won't connect.
I have been watching some youtube videos about putting the phone into download mode or even doing a hard factory reset (?) but I am quite unschooled in the art of technology and I wanted to seek some advice before attempting anything.
Please help me...........!!