Customer Rating: 
Summary: Full of detail, but not always easy to find it
Comment: For anyone coming to LaTeX from a background in mathematics many sources of help are available, but it is more difficult for someone coming to it from a feeling of dissatisfaction with the results obtainable with typical WYSIWYG word processors. When you are surrounded by people who think that Word is wonderful and that its equation editor can handle any equations you need, getting to the point with LaTeX where you can use it to advantage may seem more trouble than it is worth. You will probably start with Leslie Lamport's "LaTeX: a document preparation system", but although that is a good and authoritative start it is not really enough, as there is a great deal more to know than can be found in a short book, and in particular you need to know about all that is now available in the form of packages.
Fortunately there are some excellent sources of more detailed information, and two of these stand out: Mittelbach and Goossens's "LaTeX Companion" and Kopka and Daly's "Guide to LaTeX" . I acquired both of these about six months ago, but decided to defer posting reviews until I had discovered by experience which of them I actually used more, and although the winner is Kopka and Daly, mainly because it is much the easier to find one's way around, Mittelbach and Goossens is also a must-have book because of the wealth of authoritative information that it contains. Unlike Kopka and Daly it does not start at such a basic level that you could use it as the only source of information about LaTeX, but if you already have Lamport you can carry on from there.
Customer Rating: 
Summary: great product condition poor customer service
Comment: I have no quarrel with the product but their customer service needs some work. I had to contact them three times, and when I got a response, it was a sarcastic one. I never received a shipment notice and when I asked for a shipping date and a tracking number (if there was one), no response; I wanted to check US Postal. It was as if I was simply being ignored. Once again my item was great and better than expected. It was the customer service that knocked it down to four stars.
Customer Rating:
Summary: useless as reference
Comment: This book is pretty much useless as a reference. I bought this book as a reference for my next big document (I'm using LaTeX for some 8 years). Unfortunately I found that the index in this book is virtually useless. Yes, it does refer you to pages in the text that contain the word you are looking for, but that's as far as it goes.
"Explanations" that I did find are generally anything but intuitive, often enough sections never truly deal with what the headline suggests. One star for the examples, that I use as a guide. But generally this book keeps the wood of my shelf from fading.
Customer Rating:
Summary: Agree about frustrating aspects, but more depth than kopka
Comment: Yeah, the index is pretty appalling; yeah, learning LaTeX via this route was rough; nevertheless, short of trying to decipher the minimally commented LaTeX source code, it's the only place to find a wide variety of facts.Speaking of the source code, isn't it about time that someone wrote up a nice thorough plain-English description of what exactly LaTeX contributes to TeX, and how it does it? That way there would be a way to learn everything at the highest level: read the TeXbook, then read what I envisage. At present, the vast number of `@'-commands, which you need to grasp for writing macros, aren't documented anywhere outside of the source code.
Also, does anyone know the inside scoop on the progress of NTS/LaTeX3?
Customer Rating:
Summary: (Almost) everything you want
Comment: My personal favorite. I have been using both the German and the English version of this boock since 1996, and I just love it. Granted, the world has moved on, and many things about LaTeX have changed and still are, and yet, there is so much information in this book. I only hope the authors soon prepare an updated version including the latest developments.
