The Structural Masonry Designers Manual written by Curtin Shaw Beck and Bray is very very good as both a practical text and an introduction to the subject. It's probably out of print but Amazon.co.uk or similar should be able to track it down. It covers un-reinforced and reinforced masonry, arches, diaphragm walls, cladding panels and probably just about everything else. It is written to be used with BS 5628 but possibly not the most recent version so you might need the code as well. When I was learning to design masonry the book contained all the information I needed
