Here is what I have discovered:
The Indie Bible:
Great for where to send away for press reviews, radio stations and places that will help you sell your music
For the most part no venues are listed. If you don’t need a review this is a waste of money in my opinion.
The Musicians Atlas:
http://www.musiciansatlas.com
It comes in book form once per year but if you have a subscription they give you online access to their database that is constantly being updated. This one is great for venues, but also lists festivals. etc…
(Billboard magazine has a very similar one to this one)
The Music Phone Book:
http://www.musicphonebook.com/
This one comes out in 4 or 5 different areas of the USA. I have their midwest edition and it lists a lot of venues there were not listed in the Musicians Atlas.
So, I basically recommend getting both the Musicians Atlas AND the Music Phone Book Midwest edition.
I get both of these every year, but I only get the Indie Bible every 3 years or so.
I try to perform in other states is why I get both. If your only going to perform in the midwest area then you could get by with just the midwest edition of the Music Phone Book.