Been having problems doing this, quite frustrating as it should be a simple task. Any help would be great please.

When I attach the usb cable to the pc, only itunes loads up, however I never get an Iphone icon in My Computer. So I checked in device manager, and there is an exclamation mark icon against the digital still camera. It asks me to install the software, however after checking my iphone box, I do not have an installation disc. Which leaves me stuck as to what to do next.

Thanks in advance

installing itunes should install the appropriate device drivers.

disconnect the iphone
delete the item with the exlamation mark in the device manager.
uninstall itunes
re-install itunes.
reboot if necessary
re-connect iphone

Yeah, it sounds like one of the drivers did not install correctly, or has been interfered with since installation.

Full instructions for getting a clean installation are here for Windows XP: http://support.apple.com/kb/HT1925

And here for Vista and Windows 7: http://support.apple.com/kb/HT1923