shrooms

Kits:
https://www.shroomsupply.com/
Get the A+ kit so that you can get the casing. You can freeze the compost and casing if you have a freezer, otherwise you can get the staggered shipping.

Spores:
https://sporeworks.com
https://www.freespores.com

Spore Works seems to have a better reputation online.  Free Spores is a bit cheaper. Go for either Cambodian or Golden Teacher.

I followed the instructions on the Shroom Supply site for the most part, but the following guide also works, especially if you want to grow them in 6-quart-ish tubs like I did.
https://www.shroomology.org/forums/topic/8670-6-quart-dub-tub-mist-and-fan-bulk-tek/