You can always look in the local Yellow pages but the best way is to call a local Real Estate office and ask what offices handle rentals.
Rentals take special handling so when you do get a list of Rental offices ask some questions. Like how long has the office handled rentals? Do they have E & O Insurance? Ask for references?
With you home on the market there are special problems. You need to have an agent that Knows the rental laws for showing the home to possible buyers, for eviction of tenants or required paperwork needed for the new owner/landlord at close of escrow.