One inspiration was Alexander Saunder's op-ed piece in the New York Times about helping victims of a 2005 earthquake in Pakistan. His piece "Give Them Shelter" suggested buying garden sheds from Sam's Club en mass and dropping them into isolated regions. It is an interesting idea.
We also used several sites dedicated to a "Tiny House" movement, which we first saw in a local piece "Stuck in Vermont". Tiny houses are houses about ten-feet by ten-feet and intended to be lived in (windows, loft beds, water and the like). There are many other sites dedicated to the movement. This movement, in turn, was inspired by Thoreau and Walden, which we read excerpts from. Many of these sources stressed simplicity and self-reliance. They also dovetailed with groups looking to solve the problems of homelessness and the environment.
There are several Instructables that will support this project, but "Pallet Playhouse" is mentioned several times in the article as it has excellent information on deconstructing pallets and using their cannibalized parts in interesting and creative ways. I suggest you read it during the design phase and revisit it periodically.
Because we embraced the ideas of civic involvement and recycling we put down two simple rules:
First, everything had to be found. Because of this, we used pallets. You will see that we used a refrigerator door for the door. Even our nails were a rusted mass that we found, and much of it was bound with twine. We speculated the builders could use anything from scrap wood to crushed soda can shingles for siding or the roof. The user of this design can use their own ideas and the resources available, as more appropriate nails and ties will make your own results much more sturdy. The aesthetic, though, was renewable and found so that materials could be found at the site for free.
Second, it was designed to be moved. We hoped that the basic structure could be manufactured at a central site, sent to its permanent site as a shell and finished with local materials. Therefore, it had to come apart and reassemble easily. The main conceit is that the pallets are nailed two each into a panel. Then, all other connections come apart easily. In this way, the entire frame can be stacked and moved on the back of a truck or pushed (bound) out of a cargo plane. On site it can then be assembled.
Mainly, though, we wanted to create a simple shed that anyone could build from materials anyone could find. Adapt to suit your needs and change your own little piece of the world.