This book deals with evidence for, and perceptions of, Jesus outside the New Testament. Van Voorst has assembled all the extracanonical evidence one could ask for, and he analyzes their value in studying the historical Jesus. He lays out the Agrapha, Gospel of Thomas, Gospel of Peter, Infancy Gospels, "Secret Mark", and much more. He considers the hypothetical sources used by New Testament authors -- Q, Signs Gospel, M, and L. He takes you on a tour through the classical writings of Thallos, Pliny the Younger, Seutonius, Tacitus, Mara bar Serapion, Lucian of Samosata, and Celsus (which portray Jesus as an overall troublemaker), and then the Jewish writings of Josephus, the Dead Sea Scrolls, and the Rabbinic tradition (which yield, or mask, a magician and deceiver). However much you agree or disagree with the author's conclusions, this is an invaluable resource which "gathers together disparate texts that are otherwise difficult to find in one place" (noted by John Meier).
But the author's conclusions are in fact sound, and they serve as a corrective to the theories of those who have been thriving on extra-canonical evidence at the expense of the New Testament. To be sure, there is value in these sources, but that value is fairly limited. Taken in conjunction with John Meier's "Marginal Jew" (vol I) and Donald Akenson's "Saint Saul", the trilogy refutes any reconstruction of Jesus which relies heavily on apocryphal testimony.