If you have the time you could offer to walk/exercise dogs for your local shelter. Here they are always looking for people to interact with the animals. Then you could see firsthand what their personalities are like and if they are compatible with you.

This is what a friend of mine did and she found out she specifically didn't care for what she called "mop" dogs. She said the maintenance for their fur and keeping their poop out of their fur was too much work.