Well guys, for now I ordered a 12-pack of moving blankets. They are fairly big, like 8 ft x 6 ft or so. About $110, shipped.
I grabbed our scrim stands (pvc pipe) from the jam room and used them as a frame, as well as using the closet doors in the recording room. (Closet doors pop off the track and can swing out over 90 degrees). I was basically letting the blankets folded over themselves 4x so they were thick and draping them all around. Still not done, but a quick clap test recording before and after in the "booth" already shows a pretty big difference.
I figured I'd shoot for a make-shift vocal booth for now as that is top priority and worry about the rest of the actual room treatment in the near future. I'll see if I can get some pics up once I get it finished.