Complex sentence: Joe is the author of three books, two of them being tips for cats and dogs, and one called "It Really Does Happen to a Vet!", a diary of Joe Inglis' first year in practice.
Split into simpler sentences: Joe is the author of three books, two of them being tips for cats and dogs, and one called "It Really Does Happen to a Vet!". The latter book is a diary of Joe Inglis' first year in practice.