The world wide web. Its not so much a book but once you filter out all the bull shit it's pretty good.
Get some wild bird seed, one with mostly small round seeds. Soak over night. Take everything that floats and toss it. Boil it till its kinda soft and some kernals are poping. strain it to the point it will not drip when your squeez it then Put that shit in some pt jars.
Pop a 1/4" hole in the lids and pack with poly fill, but not super tight. Close the jar and wrap the top of the jar with aluminum foil and pressure cook for an hour. Do this at night and u can just leave the jars sit over night and not just sit there impatiently waiting for them to cool
Now put your syringe togeather, burn the needle with fire and wipe/cool off with a alcohol wipe of some sort. Take the foil off the jars and start injecting 2cc into each jar, wiping needle with alcohol between jars.
Now take the jars and put them somewhere warm, I just put them in a cupboard and let them sit till they are fully colonized ( all white).
From there you can find the rest on the internet. I did a bulk grow which is super easy so maybe look that up. I don't use a casing layer on half of mine and it did pretty good so you don't have to have casing in bulk.
This is where I started
https://www.shroomology.org/forums/topic/46-how-to-grow-shrooms-in-bulk-monotubs/
Good luck
