What equipment do I need to start growing mushrooms?

For a first grow you need very little: a still air box or a clean, draught-free corner, 70% isopropyl alcohol, a pressure cooker for grain, and a clear box or bag to hold humidity while fruiting. A pressure cooker that reaches 15 psi is the one piece worth buying early, because it sterilises grain reliably. The rest, such as micropore tape, a spray bottle, and gloves, is inexpensive.