Just received the drive you suggested. What should I do before plugging this in?
Ooooops... I see Weaselboy beat me to it...
Plug it in and format it in Disk Utility using a GUID partition Map (under Partitions) and the Volume as Mac OS Extended (journaled). It should default to these.
Then you're good to go...
In Time Machine Preferences, select which drive(s) you want backed up, and select the drive to back up to. That's it... then make at least one back up and you can set it to back up regularly after that.