Molecular motors are a fascinating class of proteins, perfected by the biological evolution to carry out a variety of functions related to force generation and intracellular transport. Although these nanoscale engines have been the subject of extensive research in the past, important aspects of their activity are not yet fully understood. This book shows how, by rather simple models, remarkable insights into the dynamical behavior of molecular motors can be obtained. The author focuses on the investigation of helicase motors, which manipulate DNA and RNA molecules. It is explained how functional conformational motions in these motors can be identified and shown that entire operation cycles of an important viral helicase motor can be traced with structural resolution. In a separate part the emphasis is put on more general model systems, which are aimed to improve our common understanding of the operation principles of molecular motors.