Sorry, I dont know of a guide......for bouldering. Some of the walls in Sabino Canyon are listed in the guide "Backcountry Rock Climbing in Southern Arizona" by Bob Kerry (the title may not be exactly right, web search for some of those words and "Bob Kerry"). You can do like I did , though, take the canyon shuttle bus up to the head of the canyon then walk down and look around. The turistas will give you and your crash pads a few odd stares on the bus, I'm sure. Bring LOTS of water.....
Regards,
Mark