The website lost my first attempt at responding to your question. (loud sounds of frustration emit from my lips) LOL!
Water is a foundational concern. The adage is "Slow the water, Spread the water, and Sink the water". In a desert, you must think in terms of capturing all the rainwater that touches your land.
If you control where the water goes, you will know where to plant your Food Forest garden guilds (a plant guild is a collection of plants that create a symbiotic web of mutual support).
Brad Lancasters' two-volume tomes on Rainwater Harvesting will serve as your bible for supplying water for your garden. They are available on Amazon.com and Chelseagreen.com, among other online resources. Other
books include Stella Otto's books about orchards and berries. Look at some of the other "greening-the Desert" threads for links that I have posted pointing to videos and articles on Restorative Pastures and Intensive Livestock Management.
You need to set for your new gardeners the task of observing the land and plan how best to use the whole property. Then determine a plan of development that starts with small steps that following actions can build on. For instance, some areas may be suitable as pastures at first as a method for restoring larger tracts of poor soil. If a self-sustaining pasture can be established, it may be possible to offer livestock herding services to
local livestock owners, which could provide funding for other garden projects.
Establish a place to
compost all organic materials, such as food scraps, manure from livestock, and other restorative
gardening techniques, such as restorative pastures and intensive livestock management techniques. I have posted links on some of the other threads on this site.
Figure out where your "food trees" and "nurturing trees" can best be established, and plant your rainwater harvest where it will support those trees. Those trees will serve as the "Anchor Plants" for the rest of your food-forest plant guilds.
Early on, establish a "seed-saving" library and a system for saving seeds, and a plan for collecting cuttings to propagate new plants from existing perennial food plants. Also, create a library for books on
gardening that can help your charges to research and teach themselves in your absence. Perhaps you can get some donations of books from the many experts on this site. The garden project
should be integrated into any literacy project that may already be in place.
I am a "soils and water" guy, I hope the plant experts will soon chime in on the best plants to use. Observe what the other farmers in the area plant, but also observe what
native food plants are supporting the local wildlife.
I will cut this comment short, but be sure to reply with any more specific questions that your situation brings up. Good luck in all of your endeavors.