I'm not sure who i bought this from but i got it quickly and it was in great shape, so kudos to them for that. The book itself is a pretty good buy but not for someone just starting out on the topic of demonology as I am. I'd gather that it is better for someone who has studied demonology for a while, and when they get stuck trying to remember how many Aerial Spirits of Solomon there were, or whether Beelzebub looked like a fly or a spider, then this book is a good place to jog the memory. But for someone starting out, you won't get a clear coherent story. You'll start reading at A, encounter your first of Solomon's many demons, and then you'll flip to the section on Solomon. You'll be intrigued and find the whole thing interesting but you'll want more than is available.
From what I've been reading, a lot of the information on a lot of the demons is limited even in the original texts in which they appeared. But still, it's an encyclopedia, so perhaps much of the information was just omitted. If you're looking for a good historical analysis of the origin of a demon, or how a "demon" evolved after its first appearance in the Old Testament, then you should look elsewhere.
The book does have good "further reading" notes at the end of each section. The suggested books are likely the ones you'd want to read first. I'm eager to learn more about the history of the origins of these demons, how their stories evolved and their legends came to be throughout history. If that's what you're looking for, do a little more research and skip this one. But if you're just looking for a demonic freak show of sorts, or you're trying to come up with some baby names that'll piss off your religious parents, this is book is for you.