I agree with proudmum.
I work with Nursery staff who work with children who use Makaton, and sometimes BSL and my advice is always to watch something special / see hear, and learn 6 signs for words they use regularly first, then start adding to them one at a time. The sign books are fine, but personally and this might just be me I find it difficult to "read" a diagram, and like people to actually show me how to do the sign. 