Reader's Oasis Books is a used bookstore on Main Street that became part of Quartzsite's folklore. It is cluttered, independent, and very much of the desert-show world, where a shop can be both a business and a roadside character.
Go for browsing rather than efficiency. The point is the atmosphere: books piled high, winter visitors drifting in, and the sense that Quartzsite's best stops do not care much about polish.