At the base, it takes a club and a liability policy. You have to sign a permit application with the C&C, show proof of insurance listing the C&C as co-insured, and work out scheduling. Honestly, Mike takes care of most of it, if you start with the insurance. Anything outside of your normal schedule requires permission plus an insurance certificate.
I think the amount of insurance required varies depending on the activity. Expect to need a 1 million dollar general liability policy, and if they only ask for half-a-million, then great! And don't be daunted by the number... a 1 million dollar general liability policy will only cost you a few hundred bucks a year. NRA sponsors insurance for gun clubs and keeps the rates quite affordable.