A little more information please. How flexable, capable, are these people otherwise? How supervised are they? Is it in the city or country and do they have the ability to go outside.

We have a local lumber retailer called home depot. They have a line of classes to teach adults how to tile, drywall, and basically use their products. They also have craft classes for kids and sell kits for bird houses, bird feeders, etc. Lots of these are glue together instead of nail together and the joints are already cut.

We also have craft centers called AC Moore Where you can get similar unfinished boxes, Laptop writing desks, sewing kits, and more that can be assembled, painted, decorated whatever. There are usually 1 and 2 dollar bins at the front of the store where you can find inexpensive things.

Most retailers in the US can be talked into donating crafts or even sending people to teach especially if they can get good P.R. in the news. A quarter page ad in the local paper is $100 but a human interest story is free.