Dinosaur Comics is something not easily explained. Wikipedia takes a stab at it, and while it gets some of the technical details across, it doesn't quite get across the peculiar humour that characterises the strip that has, since the time I discovered it, made my workdays somewhat bearable for a year and change now.
It's also one of those things that when I try to explain it to people their reactions are usually blank stares and utter confusion. This isn't something wrong with them (Humour is subjective, after all) it's just that Dinosaur Comics is rather unique.
Here, let me have a stab at describing it:
Dinosaur Comics features the same six panels over and over again with the same pictures of clip art dinosaurs every day since 2003. The gag is that while the pictures may be the same, the dialogue is always different, covering such diverse topics as the origin of superheroes, considerations of philosophical approaches, and perhaps the most awesome and simultaneously stupid novel idea, ever.
. . .hmm, yeah--you're probably better off just looking at the links.
The book is, as you might have surmised, a "best of" collection of the early years of Dinosaur Comics, from the first few relatively simplistic strips and is quite a fat little collection (250 pages, give or take) and that may be a bit daunting for the neophyte reader, because a cursory flip-through will only yield that it's the same art over and over again. It's really only by actually reading through the strips and coming to appreciate the completely bent and frequently unpredictable style that the author brings to it that it will either win you over or deter your utterly.
There's something to be said for the fact there's no middle ground there, I reckon.
In any case, I found it to be a book well worth reading, and perhaps you will as well!