Here are some pages from my sketchbook on color. I am reading Betty Edwards' book on color right now. She has you do a regular color wheel, then do tints and shades in steps and arrange the values like a clock, so as to be able to see opposite values clearly --- a useful idea, I think. I'm not following her directions exactly, as she includes the secondary colors and has both warm and cool red. I am using primary colors only, but warm and cool for each.
I love cerulean!