Yes, it is highly recommended that you hire a qualified attorney to help guide you through the short sale process. A general rule of thumb is that if you are ever given a contract of any kind to sign the chances are that contract was created by a lawyer who was looking out for the best interest of the person that is handing that contract to you.
The majority of time unsuspecting homeowners are told by realtors, mortgage brokers, or other entities that are subject to making commissions or otherwise profiting from the short sale process, that they will not have any financial responsibility if they short sale their homes. This is often not true. While a short sale may release a homeowner from their obligations under the mortgage, the underlying debt from the promissory note may still remain, resulting in the homeowner being sued later on down the road for a deficiency judgment for the difference in the amount of what they owe the bank and what the property was short sold for.