Circle Books was "A Complete Occult Bookstore" on 215 S. State Street in 1970, owned by Michael Erlewine.

http://www.aadl.org/gallery/pictureAnnArbor/a2signs/A2signs387.jpg.html

More information

I was devastated. I went to Michael Erlewine's house and sought his advice. He was an astrologer and advisor. He owned the Circle Books occult book store and he thought I should consult the I Ching. Michael counted out the yarrow stalks (I had previously only tossed the coins) and my chapter was Chapter One, The Creative.

The astrologer’s keep sloped two stories back above an old stucco garage, the home itself hidden in the shadows of the rise. In bold contrast the stucco garage framed a large Circle Books logo on its door. I’d see it moonlit, driving out to visit Dean who’d be dispatching cabs for Vets.

Erlewine: Well, the first answer to that is: slowly. In 1968 my brother Stephen opened a metaphysical bookstore in Ann Arbor called “Circle Books.” It became a real force for awhile in the late 1960s and early 1970s. I actually helped to design and build it physically and ended up calculating most of the astrology charts for customers that shopped there.