Not Sufficient Funds Checks or NSF Checks are those checks that "bounce" because the payer does not have enough money in their account to cover the full amount of the check when the payee attempts to cash it. This can result in extra bookkeeping in Shepherd's Staff as you may have to correct a deposit or void a check in addition to recording any fees that your bank charges.
Correcting a deposit can be accomplished by simply opening the Deposit Register and editing the deposit in question. Similarly, voiding a check is done by opening the Check Register and clicking the void button once the check has been selected. Recording a bank fee requires a little more thought but it can be accomplished by adding a Journal Entry between the bank account in question and the appropriate expense account.