When I bought this, I was assuming this would give me all I needed to know to play AD&D 1st ed, from a players point of view. That turned out to be a false assumption. This book will give you everything you need to create and equip a character. It'll also tell you what spells you could use. It, however, does very little to explain the game mechanics. For instance, weapons modifiers are given, but there is no explanation as to what roll with which die to hit. That part is reserved for the DM (I'm guessing, don't have that book yet).
This is a great book, but for 1st ed ad&d playing, you'll also need the DM guide. So far, for me it has serve as a reference guide for looking up spells and weapons, and character creation. Which is basically what it is, a sort of reference guide.
The book's art-work is dated, to say the least. The quality varies from very bad to acceptable. It does give off a nice flavour, it's reeks of "this is anybody's game". It's not as slick, not as polished as newer editions. It's a matter of taste, but I like it.
I haven't played a lot of AD&D editions, but I have no urge to try other editions after this. It gives me what I need, all the other stuff is just ballast, IMHO. It's a relatively clean core to play games with, all the extra's can be added at your own desire . Either make it up, or get something like "Unearthed Arcana" to add to your game.
As I've read more about mr. Gygax point of view (and was informed by a fellow reviewer), some of the information I was missing was intentionally left out, it's part of the "DM's mystique", as I call it. I was used to other games where everything was explained from start to finish, so this was new to me. It's a nice thought though, I can appreciate it.
(Oh, and IMHO: stay away from Unearthed Arcana, not worth it, don't need it. (again, IMHO))