Marguerite Meara sent me a link to Jim's Watercolor Gallery. Lots of tips and techniques, and you can sign up for a tip of the day. He has a lot of info that you don't easily find, such as how to get the correct water to pigment ratio.
He also has a lot of ideas that don't conform to the general consensus, such as different complementary colors. I haven't tried his ideas out, and I'm not sure how good they are, but it never hurts to try new ideas. Experimentation is good!