Sol-gel technologies have taken the experimenter and turned his or her world into a fantasy world of size control, materials properties, and new materials hard to realize by other more arduous methods. The importance of size and crystallite perfection with respect to properties of finished devices has been shown to be one of many critical parameters vital to high performance magnetic devices. The realm of very high and very low frequency devices seem to benefit most from the unique properties attainable from these sol-gel methods. The use of these methods to produce nanoscale particulate ferri-, para-, and superparamagnetic materials has changed our way of thinking about how to fabricate magnetic devices with properties heretofore unrealizable. A wide variety of properties may be obtained, dependent on pH, concentrations, impurities, etc. Applications of these materials to transformers and inductors are detailed, and the underlying principles and formulations of both equilibrium and nonequilibrium materials are explained.