Greenhouse Growers

Is there anything someone who is considering growing in a greenhouse should know before doing it? I'm pretty sure I've got all my bases covered except for the ventilation one...

I live in arizona and the reason I wanted to grow in a greenhouse is because it is so damn dry. I could put a nice fan on the floor level of one side and another one higher up on the opposite side but then I worry that I will lose the humidity and there will be no point to the hothouse...

Speaking of hot... it averages 100+ during the day time out here.. usually hotter for this time of year.. is my hothouse going to turn into an inferno and burn my plants?

Argh so many questions... will update..

The higher the temp, the more humidity can be withstood.
Point...
Do some research, there's plenty to be read in the cultivation forums!

ps: I'm not a pro, but they ARE here and WILL answer DETAILED Q's:D

This was the first year that I used a greenhouse to grow herb as well as other vegetable plants. California's central coast is quite mild. If it's 80 degrees out, the greenhouse will approach 100 degrees. My greenhouse is well ventilated (passively), but if it's 80 degree outside, then a fan is necessary. To be honest, I would not grow anything in a greenhouse during the summer in Arizona or California's central valley. It's just too hot. You will definitely need a powerful exhaust fan. Also, a greenhouse seems to be an ideal environment for aphids and spider mite. Fortunately for me, a Neem oil and soap solution with application every 3 days for 2 weeks remedied the problem.

You will need super exhaust/cooling.
And you will also need a way to ensure that you don't get dewfall at night when temps drop. Exhausting as much humidity as you can right around dusk should help out a lot.