TruF, if your library has "Zinn and the Art of Road Bike Maintenance," Lennard Zinn has a good first chapter discussing what to have to get started. There's a toolkit for maintainance, there's a toolkit (bigger and a little more esoteric) for light to moderate repair, and then there's a more esoteric tookit for taking it down to the bare frame and totally rebuilding it. The book does apply to C&V as well as modern bikes.

That will give you some ideas about how much you need to get, based on what you want to do.

He also identifies the tools needed for each task, letting you gear up specifically for your immediate needs. There's nothing wrong with building a tool kit based on need.

Anybody's Bike Book by Tom Cuthbertson does the same thing, but having written the book seemingly in the late '60s he's a little more rough and ready - less esoteric tools, more ways to do more with less (good ol' Buckminster Fuller).