Are members notified before an auto-renewal charge?

Yes. Members receive a renewal reminder email one week before their membership renews (and an SMS if they have a mobile number and you have SMS credits). From the link in the email they can view their membership and, if they don't want to continue, cancel their auto-renewal. They keep their benefits until the end of the current period. Members on a plan that's paid once (longer than 3 years, or lifetime) are reminded that their membership is ending and can renew from their members area.