Originally Posted by Retro Grouch
You'll probably need a chain tool, cassette tool, and chain whip. At some point you will probably want to obtain cone wrenches that fit your hubs and a spoke wrench that fits your wheels.
You may choose to have a shop remove and reinstall your headset and bottom bracket for about the same money (or less) as the tools might cost.
The tools and hex wrenches bought separately will cost more than a basic tool kit, so you dont pay extra for the tools you will never use. +1 on the headset & BB.