I'm growing this year, for the first time in a green house I built over the winter months ($250 total - 12' x 25'). The big issue is heat. You want at minimum 2 fans. One up high for exhaust, and one down low from intake (I have my intake fan in a shaded area to help keep the air cool. I also bought a cheap misting system from Lowes for around $20, and a water timer for the misting system that goes off for 10 minutes every hour (about $25 on ebay). The misting system drops the temps by 20 degrees or so by itself. Otherwise it's 105+ degree's in there, even in February.
You can also buy a shade tarp (reflective tarp) for about $20 to cover it on really hot days (Everyday around here in the summer!) - Harbor Freight.
The next big issue is height. Some of my larger plants are hitting the 6' range. I have another 4' or space so no worries there, but just something to keep in mind. Other than that, it's really no different than growing tomato's outside.
Good luck! Let me know if you have any other questions.