Okay but superficial introduction to the Nag Hammadi texts and the so-called Berlin Gnostic Codex, which provide the text of a large number of texts pertaining to the so-called gnostic religious tendencies in antiquity (generally dualistic in nature, with some varieties heavily influenced by Christianity and others being more pagan or Jewish in affiliation). The author was a major academic in the study of gnostic texts, and what he says is generally reliable. His own bias is a clear dislike of the "orthodox" version of Christianity that developed in antiquity and gives rise to most "mainline" varieties of modern Christianity. Instead, Meyer is fond of the gibberish that passes for thought in mysticism. If that's your thing, fine, but for a rational person like me, it's a lot of mumbo-jumbo.
As for the book, it's pretty simple. It gives a *very* general introduction about the Coptic language into which the surviving gnostic texts were translated from Greek and a little story about the discovery of the texts at Nag Hammadi in Egypt in 1945. The area had had a number of monastic communities in late antiquity, and perhaps it was a decree of Bishop Athanassius against the possession of gnostic texts that led local monks to hide them in a jar, where they remained until some locals found them by accident.
The book doesn't really discuss academic arguments as such, and the closest it gets to evaluating modern interpretations comes in an introductory chapter on the study of the (then) newly discovered texts. Meyer cites with approval (without really being too clear of his own view) Karen King's view that it's hard to actually conceive of a "totality" of gnostic thought. Instead, we should talk about various "narratives" of Christianity, and Meyer apparently thinks that the gnostic texts about Christianity, which differ very markedly from the "canonical" texts accepted by the orthodox tradition, are an equally valid indication of the Christian experience. In particular, he doesn't really discuss the question of the "real" Jesus and the relationship between "him" and the texts through which we know about him, though Meyer does suggest (again without being too specific) that the so-called Gospel of Thomas may be as valid a guide to the throughs to Jesus as the traditional gospels (and the Q-source that is thought to be recoverable from the texts of Matthew and Luke). While the case is perhaps arguable for the Gospel of Thomas, it seems pretty obvious to me that the large majority of the Nag Hammadi texts are later creations in which gnostic ideas as superimposed on a pre-existing Christian tradition. While there can be no doubt that gnosticism represents a legitimate strain of religious through in antiquity, Meyer is implicitly interested in "delegitimizing" the absolute claims of orthodox Christianity in order to make way for the sort of (self-contradicotry) thought reflected in the gnostic texts. This is an argument about modern religious feeling that has little interest to me (and is not a matter of historical interpretation).
Meyer identifies five major "categories" among the gnostic texts:
a) Thomistic (i.e., revolving around the figure of Thomas),
b) Sethian (pertaining to the biblical figure of Seth and interested in the nature of the secret knowledge behind gnosticism),
c) Valentinian (going back to the teachings of Valentine, a second-cnetury figure in non-orthodox thought),
d) Hermetian (relating to the mythical pagan religious thinker/god Hermes Trismagistus), and
e) a miscellany of uncategorizable texts.
There's a chapter for each of these categories, with each concentrating on a few representative texts. There isn't all that much analysis, and a lot of quotation of whacky texts. This is probably okay as an introduction for a layperson, but I didn't find it very intellectually satisfying. At the end, there's a long appendix giving a brief summary of each text. Again, not much more than paraphrase.
So, if you want a general sense of what these texts are about and don't want to go into much depth or analysis, this book is probably okay for your purposes. Also, if you dislike traditional Christianity and prefer a more personal/mystical religious experience, then you'd probably like his "take". If, on the other hand, you want to have an intellectual analysis of the documents in their historical setting, this book may be a disappointment.
One thing that gets to me is that the translations are mostly Meyer's own, and he's the sort of translator who is willing to distort the text to suit modern sensibilities. This means that manifestly male-oriented language is "effaced" with circumlocutions like "one" instead of "he" or the generalizing plural. This may be okay if you want to rewrite traditional religion to conform to your own sensibilities, but it definitely is not okay when translating ancient texts. If some ancient writer calls God "he", then by God the translation should say so!