Anybody know about growing mushrooms?

[AndyS]

I got a kit that consisted of a brick of what looks like compressed sawdust with white paint on it. Followed directions and harvested about 4 oz of oyster mushrooms but this isn't cheap--$15 for the 'kit'.

Liquid spores can be had for a few $ but I need to come up with my own growing medium. Google searches don't do much for instructions and there is a heavy emphasis on sterilizing everything.

Sterilizing? They grow wild in the woods fer crissake.

Any help appreciated or links to good beginner's books.