You should consult a real estate professional in the town where the property resides in order to confirm the rules in that state, but in general you should have no issues listing the property for sale while it is tenant occupied.
The property listing will typically need to note that the property is tenant occupied and whether the buyer will be expected to honor the existing lease or if the tenant has agreed in writing to an early lease termination once the property sells.
Hope that helps to give you a general idea.
Benjamin Harris, Broker
Rational Realty, LLC in Pensacola, FL - Wed Nov 5, 2008