"Rhythmic Fingerwork" and "Piobareachd Fingerwork" by James McGillivray are incredible books about developing good bagpipe technique. These books are full of exercises designed to improve your playing. These books are not beginners books. Every instrument has one if not many of these types of books written for it. I believe that these books are the first if not the only great technique books for the Great Highland Bagpipe of Scotland. They sell for $46.00 each.