Not bad. I just quickly scanned it, I'll read it in more detail later, but a couple of things stood out. First is nothing more than a personal take on the graphics, but I was puzzled by the uneven green lines on the opening page, not sure if they are effective.
Second, I'm not sure about your "voice". Most of it reads very straight forward stated as facts, but occasionally there was an "I feel" or an "I recommend", these felt out of place, and while what I read is accepted practice, it might read better if it was reworded to eliminate the "I"s. Also, not sure of your audience. If it's for the beginner or early intermediate, it might need to have some of the more technical aspects explained in more detail, I could see my non-techie brother's eyes glazing over in various parts of the document.
I also think the Plasma section got short shrift. The LCD section if very well rounded, but Plasma gets a couple of paragraphs? Also HDMI audio might be expanded upon, touch on issues of DD pass through or lack of it via optical. Calibration could also be expanded a bit more for beginners.
I think it's a great effort and it is very informative and I think it will be a good help to many. Thanks for the effort.