Some book do make mistakes and if they have a web site you can go there. I have found corrections listed for books and patterns. You might want to check this out..
Originally Posted by seasaw2mch
I have a book now that I am finding out the measurements are wrong for the blocks they show. I have wasted 2 yds of fabric because I cut them out "by the book" and now they don't work. I finally had to draw the blocks myself to get the pieces right. So I would suggest not buying the books at all, bring your camera with you and take pictures of the blocks you like and then draw them your self. That way you have a permanent pattern as well