So first order of business is the bed.
I can cut and put screws into wood, I can even use glue and come up with ways to use hinges, but constructing a mattress was something of an enigma for me...

I called some places and got outrageous prices for custom made foam mattresses (and I'd need two if I wanted it to fold!)... and then we went to IKEA. There we saw a nice 4 foot wide futon with a two piece mattress. Fortunately IKEA sells the mattress and futon separately, the mattress costing about $90. The two halves were not the same width, but it was close enough to perfect - at exactly 6 x 4 feet together.