Here is a great site for some good info on using a natural approach, long term sustainability in beeking and using top bar hives:
http://www.bushfarms.com/beestopbarhives.htm
http://www.bushfarms.com/beescerts.htm
http://www.bushfarms.com/beestopbarhives.htm
http://www.bushfarms.com/beescerts.htm