Greenhouse in Ohio

[Corsetière]

So my boyfriend and I are incurable plantheads and a few of our plants have grown to an alarming size - like his 15 year old ponytail palm that is brushing our ceiling. My orchid collection keeps growing in numbers and it would be nice to have a better environment for them. As a result, we are getting more and more serious about building a greenhouse but I am not even sure where to begin researching everything we will need. Though I'm pretty sure that we would like to build it custom, not use a kit.

If you would be so kind as to advise me..
1) Are there any threads on this forum you recommend? Or any books I should read?

2) If we are going to do it, we want to do it correctly and have heating for winter and the proper air circulation, etc. Are there particular brands you recommend for heaters and other equipment?

3) Does anyone have experience having a greenhouse in the Midwest United States? Anything you wish you had done differently when you built yours?

4) Those of you in cold climates, may I ask what one might expect a common winter heating bill for a well built greenhouse to be?