The Complete Idiot's Guide to Music Theory
This updated and expanded edition of The Complete Idiot’s GuideÂ® to Music Theory breaks down a difficult subject in a simple wayâ€”even for those who think they have no rhythm or consider themselves tone deaf. With clear, concise language, it explains everything from bass-clef basics to confusing codas. This new edition
Great book if you want to learn something to impress your neighbors and friends.
I also haven't tried the ear training course, but that the book includes this as a CD seems like a useful plus.