Of course, children's books are great resources for just about anything; they describe problems and situations in simple, unaffected language.
As to your desert problem, doesn't it depend on what kind of desert your characters find themselves in? I live on the edge of what's called the "High Desert" in central Oregon. Yet the area is vastly different from the Saraha or the Mojave. I believe the definition of desert is barren terrain and low rainfall. Thus, the Antarctic qualifies, but is as different from what most of us conceive as 'desert' as is the Saraha. The surface of the Moon also qualifies.
Assuming your characters are in a Saharan-type desert, sand, hot climate, no water, etc., the biggest problem they'll face is dehydration. They'll want a good supply of water, which to mammals, anyway, is in a desert, the more valuable than gold. This is why in North Africa, oases are so crucial. Commerce revolves about them, wars are fought over them, all roads lead to them ... You get the picture.
As for clothing, think of pictures of North African nomads; they wear loose clothing in layers that almost completely covers them (unlike golfers in Palm Desert, Arizona :lol ). They would wear some sort of sturdy foot covering.
Questions: How are they travelling? On foot? In some sort of vehicle? On the back of an animal? Is this trek a source of conflict? Are they perhaps without some necessity that would make the journey across the desert comfortable?