The United Way of Greater St. Louis is seeking volunteers to help fill over 300 positions at 96 agencies through its Summer Volunteer Guide, an online tool featuring local volunteer opportunities. The Guide can be found at www.stlvolunteer.org/syg. “We’re excited for a fun summer of volunteering as local volunteers discover the joy of helping neighbors in need and advancing the greater good across the St. Louis region,” said Rick Skinner, Unite…