Currently Canadian citizens can visit Panama as tourists for up to 180 days without any special visa. It's a good idea to make sure each person's passport has over a year left on it if you're coming down for a six month stay.
(Good rule of thumb for travel to any country: make sure your passport has more than 6 months left before it expires.)
Panama is a popular destination for tourists and expats because it's generally safe and prosperous, you can read lots more more about it in International Living magazine (visit www.InternationalLiving.com, log in/click "members site" to search the archive).