I would like a list of the best resources on the web for hair coloring.

I'm looking for sites that explain home hair coloring options, what's
available, provide information on how to, and that suggest how to fix
problems.

Additionally, I'd appreciate it if you can explain how one makes heads
or tails out of all the available home hair coloring products that you
see at the drugstore and how to decide when to seek professional help,
and what's the difference between home and professional coloring.

If there are any product companies with affiliate programs or other
hair coloring affiliate programs, I would be very interested to learn
of these as well.