Churches in America is a little study book put out by my denomination, geared toward Sunday School teachers and the like. It's a look, from a Lutheran perspective, at the different denominations in America, including ones that we would say don't fit the definition of Christian. After a brief introduction of the whole concept of denominations, it looks at the history and distinctive doctrines of each group, starting with Lutheranism and spreading out to different groupings of churches. It's not an exhaustive reference--it's really only waiting room material--but it does a fair job of giving the basics of what each church would teach.
--J. ( )