@Michelle236
Michelle - it;s up to you to lay down the rule of the house for both short term, and more importantly for long term guests. However, you should do this before your guest books so that there is no misunderstanding.
In my view anyone staying longer than a week is really a lodger and is sharing your space and needs different guidelines and rules than someone just in town for a few days. You would never dream of sharing a place for 4 months with someone while a student for example and not talking about cleaning, cooking, responsibilities etc - and AirBnB is no different.
Most hosts tell long term guests that there is at least a monthly cleaning fee - if not weekly. This means that you take on responsiblity for clean bedding, towels (weekly) and cleaning of the room. It means you can keep on top of your property and not be surprised when they move out if there is any mess. It;s up to you to decide how to arrange this in advance with your guest. Also, up to you to decide on whether say after the first week you provide toilet paper, shower gel etc.
All payment is done through AirBnB - you cannot change that in any way otherwise you are not protected by AirBnB if there is a problem. Search for Long Term bookings for information on how your guest will pay and when you will be paid.
Likewise, if you have a security deposit in place, then search for this on the site and it will tell you how and when that can be used.