The Shroomery is an excellent resource, you'll find step by step guides there detailing the different methods.
Indulgence of any psychoactive tryptamine (psilocybin is a prodrug for psilocin, meaning it metabolizes into it directly: 4-HO-DMT) is not to be taken lightly. The experience is more likely to be a smoother ride for those of an empty mind. Either the blissfully ignorant: those who are not really concerned about themselves or anybody else, or in contrast those who possess an extreme degree of mental and emotional stability.
In the growing of [any] mushrooms the key is in maintaining sterility in the environment, especially during inoculation of the substrate (jars typically) which must itself be sterile. You can either acquire an adequate pressure cooker for sterilization, or order substrate jars which have been pre-sterilized. It has been a long time since I ordered any, but I assume they are still being sold as they are also suitable for growing edible non-psychoactive mushrooms. You might also need some kind of heating pad or alternative constant heat source, at least during incubation. On a small scale you can just use plastic tubs as your terrarium and open the lids a few times per day to allow fresh oxygen (which mushrooms breath). The environment you keep the terrarium in also must be clean enough; there are mold spores everywhere. Lysol is a good thing to have on hand and use prior to allowing for air exchanges, but the room itself should be cleaned regularly while the terrarium is sealed. I am pretty sure you can also use a diluted hydrogen peroxide solution inside the terrarium (which must be kept very humid) to help kill foreign fungi spores.
If you wanted to make air exchange possible without your intervention, any holes cut into the terrarium should include adequate filtration measures to block out foreign microbes. The more complicated aspect of the process is 'casing', which isn't required for the mushrooms to grow on the substrate but significantly increases yield. After the fuzzy white mycelium has fully enveloped the substrate within the jars, they can be emptied into the terrarium and will soon begin to form pins (primordia) that may grow into larger fruits. The alternative is to instead break the inoculated substrate up into pebble-sized pieces, which is then spread out into a container (aluminum baking pans are good for this), which has been lined with a thin layer of something like perlite or vermiculite and possibly some additional substrate- completing your 'casing layer'. Again everything must be sterile, and it takes some additional time for the mycelium to re-integrate. Once the mycelium is seen through the substrate (note you don't want to allow it to progress much on the very surface) pinning is initiated by reducing the temperature within the terrarium to mid-lower 70's, introducing fresh air into the terrarium to reduce carbon dioxide levels, and some amount of light may be required but you shouldn't need any actual lighting within the terrarium.
Hope that helps as an overview, so reading the guides on the shroomery will really allow you to understand the process and give further tips on how to create the environment the mushrooms need.
