you may think it's strange but when I'm going through magazines or flyers I rip out pictures that I like. They pay a lot for those advertising agencies to come up with colours so I take the ones that I like, and a pattern that I like and try to match the colours I use to be similar and the same ratios as the photograph. Paint stores are GREAT for it. They have suggested colours that go well together and then I just go from there. As an example, look at the cover of Martha Stewart living this month. it's a light blue with punches of orange and white SO I'd use that blue colour as a main with the orange and white as accents.
PS: Food magazines are great for colour choices. Everyone likes to look at food!