Once you have accepted an offer from a Buyer, have your realtor forward the Agreement of Purchase and Sale to your lawyer, and they will begin preparing your sale documents.
The Buyer will have a certain amount of time to arrange satisfactory financing, a home inspection and in certain cases a water and septic test, if there is a well and septic on the property. The condition of the lawyer review of the Agreement will also take place in this time period. Your realtor will update you with any issues raised by the Buyer during condition period. Once the condition date has passed and you have not heard of any issues from your realtor or lawyer, you can consider the sale to be firm.