Worldwide Guide to Homeschooling by Brian Ray -- This book lists results of many studies of homeschoolers' results. A pocket-sized book, it is an outstanding one to keep nearby to help answer those difficult questions and objections.
Dumbing Us Down, The Hidden Curriculum of Compulsory Schooling by John Taylor Gatto -- Written by an award winning, former public school teacher, this book explains what the REAL goals of public education are. It is a quick read (only about 100 pages), but you will be shocked and amazed. This is another great book to show to relatives who wonder why you are homeschooling.
100 Top Picks for Homeschool Curriculum by Cathy Duffy. -- In addition to reviews of materials, this book includes an explanation of four personality types: Wiggly Willy, Perfect Paula, Competent Carl, and Sociable Sue. Suggestions as to materials and methods to work with each of these personalities are covered.
Homeschooling the Child with ADD by Lenore C. Hayes -- Informational book about how homeschooling can help your ADD (and other disabilities) child and why the "traditional" environment may be failing him.
Homeschooling is hard work, and the experienced parent needs some encouragement as the "going gets tough." For the Children's Sake by Susan MacAulay -- An interpretation of Charlotte Mason's gentle approach to homeschooling, focusing on a whole family approach to a positive learning atmosphere.