For a general pattern book I have enjoyed "Trout Flies" by Dave Hughes. It is not a step by step, but does give some steps and is pretty comprehensive. I also like John Barr's book. He has 20 pretty darn good patterns in there with excellent step by step photos taken by Charlie Craven.
I agree John Barr's book is good, but it is only his patterns. I recommended Charlie's book simply because it is equal to John Barr's book in terms of quality, but with a lot more general patterns and many more of those "beginner" flies.