Need advice for a newbie build
 

Ok, so, we've FINALLY moved into our new house and my husband said I can build an orchid case for my miniature phalaenopsis collection on this counter.
Attachment 103163
Sorry for the dim light and boxes, but you get the idea. It's 3ft tall, and the build area available is 3ft wide, 12ft long, and it's 3ft from the counter top to the bottom of the decorative lights that are hanging above it.

Here's a couple photos of a greenhouse design I want to scale down for this, taken from an old book.
Attachment 103164
Attachment 103165
I like the shape of it, I should be able to have long lights span the length of the case while still having access panels/doors along the sides and a few smaller ones on the ends for electricity and such.

Aaand that's all I got sofar. No clue what to do next as far as fans, lights, humidity trays, etc. I need advice!

That is a nice design. I hope you build it. I recommend you go over FirstRays,com for ideas on lighting, watering, humidifiers, thermostat, and other products. Each product has a description, which is edifying.