Determine the oxidation numbers of each species in the reaction by logical deduction, or by looking at the compounds in the chemistry reference guide.
Compare the products and reagents to determine which compounds underwent a chemical change. Compounds that do not undergo a chemical change are not potential actors for a redox process.
Compare the oxidation states of the changed chemical compounds in the products to those in the reagents. Again, these oxidation states are easily found in reference literature. If there has been a change in oxidation states then a redox reaction has occurred.