Flora -I agree about sheet music. I feel that it is more often than not a hindrance to learning to play. Recently we have had several people ask for banjo lessons (Ha Ha I hear some say). They all turn up with books on how to play the banjo (Guitar etc). I tell tham to throw the book away and then teach a couple of very easy bits that lets them see that they can produce something that sounds good on the instrument. I use this as a basis for the rest.
Its always good to send them away feeling they can play something.