I need to stop itunes from syncing my contacts. But to do this, I need to edit the sync settings before i plug the device in. But those settings arent available until after youve plugged the device in.. chicken, meet egg. Any ideas on how to do this?

I suggest you load up iTunes, connect your device, and then immediately swipe the screen when it comes up with message "swipe to cancel sync" (not sure if that's the precise wording). Bingo, you can change your settings and then manually sync.

I remember that the Application preferences of iTunes(CMD+,) has got a panel to configure the devices, including an option to choose whether or not sync automatically when the devices connect.
But this was on a Mac, not sure if the PC version works the same way.

Yes, PC works the same way.