This is the first of these "American Legend" ebooks I've read. They seem like a good idea: Very short (maybe 10,000 ... more like a long magazine article than a short book) introductions to some influential person's life and career.
Anyway, as for this one specifically: I knew a bit about the life of Walt Disney before, so I don't think I got much new information from the book, but there was nothing that seemed off-base. It certainly doesn't mythologize Disney; in fact, it's much more critical of his personality quirks than most popular versions of his life seem to be. There's no credited author, so you have no sense of who wrote this and what their perspective might be -- but there are some references to suggest at least minimal fact-checking.
Overall, this book's greatest strength -- brevity -- is its greatest weakness. It's a quick read so you can't get bored -- but if you get interested, it's got no depth. Personally, i got it as a freebie so I can't complain. For three bucks... eh... you may be better off with Wikipedia.