Garden House

I've built several garden houses and have always thought I could do it better next time.   I'm going to collect some resources here.  I like that term "garden house" better than green house 

The video above shows some good ideas for making a strong poly tunnel.  He also said he would use metal conduit next time.  I too  have built this type of tunnel and found that the wind eventually shifted the tunnel such that the whole thing became lopsided.  An important thing to notice is how low he installs the brace.  If placed too high rain will begin to collect on the top and pull the plastic down until you have large ponds of water hanging down above your head.  Make sure the brace is low enough that the water will run off.

Here are a couple more links I like:
http://www.greenhouse.cornell.edu/structures/factsheets/pgm.pdf
http://www.motherearthnews.com/organic-gardening/hoop-house-zm0z11zmat.aspx