This book provides an excellent theoretical introduction all of the major concepts and models used in phylogenetics. It considers the more recognized models implemented in all the standard software packages such as PHYLIP, PAUP and PAML as well as considering more recent developments in Bayesian analysis implemented in software such as BEAST and MrBayes. Anyone with a good grounding in calculus should be able to follow this book without any problems, although i wouldn't recommend it for pure biologists. The book " Bioinformatics and Molecular Evolution" by Paul Higgs and Teresa Attwood is a much more gentle introduction to almost all the same material, but without going overboard on the mathematics.
What i also like about Yang Ziheng's book is his style of writing. I think there are few scientific writers who can express themselves with such clarity, something that comes through in his journal publications as well.