I'm getting a new tone generator and probe for work, but I've never used one
before. I get the idea, and I've read the documentation over the Net, but
are there any good Web sites with primers on how to use these things?

I'll be using it to trace preinstalled CAT-5 cable in private homes for
setting up home networks. They usually all come together in a large bundle
at one end, and it just takes too long to twist a pair of wires together in
one room and check for continuity on every wire at the other end.