We have learned that our Tenant has been arrested for growing pot with intent to sell. He has since stopped paying rent (one month, so far). How do we begin eviction process?

Where? It varies by State.

Was he growing the pot on your property, if so why did you not evict him then.
But if he is not paying, evict for non payment as a landlord I am sure you would not be in business and not know how to do a standard eiviction.

Do they have a lease