I've taken advice and registered for a Defensive Shotgun class. Bringing slugs and buckshot as asked seems clear, but most ask to bring lots of birdshoot. Why is this and what birdshot should I bring?
Go to Wal-mart and get something inexpensive. I believe you can get bricks of 100 rounds for under $ 15.00. You might be able round something up that is cheaper.
Dave McC is right on. Perhaps 1 oz loads but something lighter than a 3 Dram load if available.
Cbjessee--Where are you taking your class? Be sure to give us a review when it is over!
They want birdshot so you can shoot lots of rounds without making your shoulder (too) sore and/or building in a bad habits. You certainly need to practice and familiarize with 'duty' loads (buckshot and slugs), but most of the shooting will be done with birdshot.