My favorite bookstore is called "Lady of the Lake." There is one location in Idyllwild, Temecula, and then one somewhere else (I'm not sure where).
They feature books on the occult, and metaphysics. And I like that they have a selection of older stuff (not just new, fluffy, stuff).
They also sell other things besides books; jewelry, crystals, candles, aromatherapy, incense, even swords!