From what I have seen from books, they are mostly a review of various moves. DVDs are similar and they don't provide a person who will correct your moves if it's done wrong. You can learn something from books and DVDs, but you can't learn a martial art from it.
Join a school. You might spend £20 on a few DVDs, with that money you can get around 10 lessons, that can be around 15 hours of lessons. Your money is used better if you take lessons from a teacher.
