Once you have identified that the hindwing is larger and shaped differently than the forewing then you have determined that your specimen is a Dragonfly, or a member of the suborder Anisoptera. Dragonflies are typically stockier than Damselflies and usually perch with their wings open.
To determine what family a specimen belongs to we will first look at the eyes.
Are the eyes widely separated ?
Do the eyes come close to one another or touch ?