The best book I've seen on the L&B is the Oakwood Press publication "The Listowel & Ballybunion Railway, (Locomotion Papers Number 33)" originally by AT Newham (1967), 2nd edn compiled by Michael FOster and an extension of the original,1989 - ISBN 0-85361-376-1. Contains a lot of historical detail, photos, drawings of stock, track plans etc. According to Oakwood website - http://www.oakwoodpress.co.uk/lp.htm - a new edition is due. Occasionally turns up on eBay or may be available through the specialist booksellers.
Joe