I would like suggestions on how to keep the sun/heat off of a skylight for cheap and so send me any suggestions, I can get up to the roof myself :)
How about some window tinting film sold in the auto section at Walmart or similar. You'd apply it to the inside, and it comes in varying darknesses. It won't damage the glass, either. We've tinted our children's windows before with it when we were in rentals that came with window coverings that just didn't block enough light.
Someone mentioned using space blankets on another thread to block light in windows. Would something like that work? Taped to the inside of the skylight. Space blankets are uber cheap.
And while I theoretically love the idea of skylights, the ones I have seen always make the space so dang hot!
I've made a curtain for inside before.
I made a rectangle of fabric, slightly larger than the window and hemmed the sides. Along the top and bottom of the curtain I sewed a casing. I also sewed a couple of tapes to the bottom edge of the curtain.
I used a curtain wire, threaded through the bottom casing, the fixed into screw eyes at the bottom edge of the window.
At the top of the window I screwed a couple of cup hooks into the wall. By threading a dowel through the casing at the top of the curtain and resting it in the cup hooks the curtain stayed in place covering the window. When I wanted it out of the way I rolled it up and tied it with the tapes attached to the bottom edge.
It's kind of hard to explain but was pretty easy to make and worked well.