There are over 375 active clubs registered with NAFA across the United States and Canada. You can
browse these clubs by state/province here.
You can also check out the NAFA Regions page to find out what region you're in, who the Regional Director is in that area, plus how to access local info like regional flyball websites and Yahoo groups. Regional Directors are a great place to start if you are new to flyball (or just new to the area) and looking for a team to join.
Or find a flyball tournament near you and go check out the action firsthand.