I have long enjoyed the Valdemar series, so I’ve had this book on my radar for a bit, and managed to snag it from Bookmooch. I will say, I think I’m glad I didn’t really pay for it. It’s definitely the kind of thing that was much more useful before the internet came along. And actually, this was just late enough that there are web resources in the book, which were a hoot. (Web rings. I’d totally forgotten about web rings.)
So I’d say, if you find this used, there is a nice little novella, and some interesting interviews, but I bet you could find the information about the world of Velgarth online now, and there’s nothing wrong with that.