I've been learning to grow vegetables for about four years now, and am still a novice but am getting better each year. I live in the south east and we got a tremendous amount of rain this year, so not only mine, but everyone's garden was pretty bad this season. I had made a little 4'x12' greenhouse a while back, and only planted 2 tomatoes in it, but they have produced great, and still are. I think my garden produced about 4 tomatoes, compared to dozens from those 2protected plants. So after seeing real results first hand, I'm building a greenhouse. I found a deal on some galvanized pipe and have the frame up for a 18'x21' enclosure. I think I'll have raised beds to help my back out as I get older, will have a thermastat controlled fan, and am using chicken manure and rabbit pellets for fertilizer. I have two creeks and a plastic septic tank for water storage too, but even with all this, I realize there is nothing better than real world experience. Has anyone out there got any experience with a greenhouse, and have any pointers or warnings of mistakes?