I suck at building color palettes from scratch. I've read a dozen tutorials and watched a handful of videos and if you asked me to put together 5 colors that look great together I couldn't. I think building great color palettes is a genetic predisposition, like drawing or writing good poetry or liking mushrooms. If you're not born with it, you won't have it.
That said, the Internet does a great job at augmenting our deficiencies. You don't have to be a color aficionado to choose a great color palette. All you need is a basic understanding of the effect of color on emotion, a little good taste, and a tool like COLOURlovers or Kuler by Adobe.
