Barry J. Book has a private practice which focuses exclusively on family law. He is regularly appointed by Milwaukee County judges to serve as guardian ad litem (GAL) to represent the best interests of minor children, and acts as mediator in disputed family law matters. He is a member of the Leander J. Foley, Jr. Matrimonial Chapter of the American Inns of Court, the State Bar of Wisconsin Family Law Section, Milwaukee Bar Association Family Section Bench/Bar Committee, Co-chair of the GAL Subcommittee, and a board member of the Divorce Cooperation Institute and of the Society of Family Lawyers. He is regularly invited as a speaker at GAL seminars.