From the intro:
"Familiars have long been a part of the arcane tradition and their fabled past has been portrayed in many a yarn, old and new. They are depicted in the tales as dedicated servants, faithful confidants, and in some cases as unwavering soul mates, but no matter how they are described one thing is certain: familiars are more than just simple companions to keep your feet warm on a cold winter’s night. They are in truth magical beings, bridges as it were, between the mages they serve and the arcane power their masters wield. Armed with this knowledge it is the aim of this tome to explore the world of the familiar and to comprehend its unfamiliar nature.
Herein shall be addressed an abundance of issues dealing with familiars and in order to give the work a coherent structure the first section shall be dedicated to an overview of the salient topics related to familiars. In this section we shall discuss in short many of the fundamentals that shall be dealt with in more detail later in this work. Also to be found in this section shall be a brief discussion of the various types of familiars, from aberrations to magical beasts to undead."