Having previously failed to grasp the subject after purchasing two other books on hyperbolic manifolds, this book, now in an edition revised in 2005, finally gives me hope I may one day begin to understand hyperbolic manifolds, and, more importantly, given me faith that is worth making the necessary effort.
The author has succeeded in his aim of creating a work of reference that is largely self-contained: the "foundations" mentioned in the title are laid very deeply - roughly half the book (7 chapters out of 13) is used to give a detailed presentation of background material. For instance, there is an entire chapter on Spherical geometry, and one on the classical discrete groups, (which includes a detailed proof of Selberg's lemma).
All this background material is presented both carefully and well, so that a substantial part of the book will prove a valuable reference to non-specialists.
Chapters 8 through 11 are the chapters specifically devoted to manifold theory, presenting first surfaces, then 3-manifolds and then n-manifolds. Chapter 12 introduces Kleinian Groups, and contains several very nice proofs about limit sets, which are the first I have seen that have made me really believe manifold theory could be a way to make the subject of Kleinian groups easier to understand rather than harder.
The final chapter concludes with a proof of Poincaré's Polyhedron theorem.
The author suggests that the material in this book could be studied reasonably thoroughly in a one year course, but that to cover it in depth would take around two years. So, having only owned this book for some six weeks at the time I write this, I am probably reviewing it too soon, and freely confess that there is much in that I do not understand as yet (and I think I will require nearer two years than one to work through the book properly). But I already feel justified in recommending it warmly because I am confident most potential purchases will appreciate not being endlessly referred to other works or "well-known" results in the development of the material, and agree that this is a book that will repay careful study and strikes a very nice balance between algebraic, geometric and topological points of view.