Port Washington: Review five popular social media networks and the benefits of each, how other businesses use social media, what to create, how to tell if it works and more, 7 p.m., Port Washington Public Library, 1 Library Dr., free, pwpl.org, 516-883-4400. BUSINESS MENTORING Rockville Centre: SCORE volunteers provide guidance on starting, managing and growing your small business, 10 a.m.-1 p.m., Lakeview Public Library, 1120 Woodfield Rd., free, call to register for an appointment, lakeviewlibrary.org, 516-536-3071.