Legends of Imagineering
is basically a collection of biographies, focusing mostly on imagineers who had an impact on early Disneyland. Each one reads much like a mini-bio in a magazine might, with some really nice behind the scenes pictures.
This is definitely a book for Disneyphiles, especially those of us who tend to obsess over the parks (guilty). Because of the format, a basic knowledge of Disney park history would be really helpful to follow what's going on. I don't mean dates and specifics, but just knowing that, say, Pirates of the Caribbean wasn't an opening day ride in Disneyland would make your reading smoother. That said, I highly doubt anyone who doesn't have that background knowledge would even be interested in a book like this. This is very much a book for somebody who can already name at least two imagineers, and who will be excited to read about their favorite.
There's some really great information and stories in here for those of us who are obsesssed with the parks. I tend to read more (a lot more) about Disney World, so somebody who focuses on Disneyland might not find so much new information. But I'd never read about the feral cat colony in Sleeping Beauty's castle, and I didn't realize just how many of the early imagineers had started in animation at Disney. I had not, for instance, realized that the Marc Davis who animated Maleficent was the same Marc Davis who painted the stretching portraits in the Haunted Mansion.
For a fan of the Disney parks, especially Disneyland, this is probably a must-read. But you'd have to be a pretty big fan to maintain interest.