Materials with anisotropies giving rise to perpendicular magnetization are important for optical data storage applications. However, the microscopic origin of the anisotropies is not well understood. It is now widely recognized that understanding the origin of surface and interface anisotropies is one of the most important problems in magnetism. Ultra-high vacuum deposition techniques allow the sequential deposition of layers of several elements with great regularity, and little interdiffusion and contamination at the interfaces. The microstructure of the resultant multilayer materials can vary from amorphous, or polycrystalline with only short range order, to high quality superlattices with long range structural coherence in all three dimensions. This paper gives an introduction to rare-earth/transitionmetal and transition-metal/transition-metal multilayers and superlattices. Sputtering and Molecular Beam Epitaxy (MBE) processes used to grow these materials are then described, as are the in situ and ex situ characterization techniques used to determine their electronic and physical structure, and to measure their magnetooptic properties. Some of the magnetic and magneto-optic properties of materials produced by sputtering and MBE related to optical data storage are discussed.