what do you have to file and/or inform the renters of to in compliance with any legal issues?
You must give proper notice in order for inspections. However, I offer an incentive to show the unit and allow inspections with less than legal notice.
This will depend on your specific jurisdiction. Maryland and DC have tenant first right of refusal laws. The DC version is very landlord unfriendly. If you sell through an agent they should know most of the laws. (although remember agents are not attorneys)
I am aware that provisions of The Maryland Condominium Act (Maryland Code, Real Property, Title 11) govern the tenant’s rights to buy his unit when the tenant is an occupant of a multi-unit dwelling that is being converted to condominium ownership.
I am not aware of any other provisions of MD law that give a tenant the right of first refusal for a simple arms-length change of ownership. Could you direct us to the applicable code sections?