If you can somehow gather 30 40x48 inch pallets, you're more than halfway there. Just grab a hammer, saw, nails, and drill and you're ready to get to work.
The instructions at ReadyMade for a 100-square-foot Tiny Pallet House are pretty thorough. We'd love to know if anyone tries this out. The "house" seems like it would make a great backyard shed and/or office.
Image: Tiny Free House