In the last few years, hopes have emerged that simple concepts could perhaps explain the extremely complicated biomolecular processes which are now known to a greater accuracy. In parallel, powerful methods in physics, especially nonlinearity and co-operative effects, have been developed. They apply especially to biological phenomena and can explain coherent excitations with remarkable properties. This book provides a pedagogical introduction to the theory of nonlinear excitations and solutions in a biological environment, and also to the structure and function of biomolecules as well as energy and charge transport in biophysics.