Pembroke’s two public beaches are open for the season and swimming lessons will begin at both locations on Monday. The beaches are at the town landing at Oldham Pond, on Wampatuck Street, and Little Sandy Beach, on Woodbine Avenue. Both beaches are staffed by lifeguards daily from 10 a.m. to 4 p.m. Anyone interested in signing up for swimming lessons can do so through the town’s website, www.pembroke-ma.gov. Beachgoers at both sites may notice improvements that the town carried out this month — replacing the aged wooden docks with polyurethane ones, and adding a polyurethane boat dock at the ramp on Oldham Pond. The project was funded through $50,000 appropriated by Town Meeting last November, according to Town Administrator Edwin Thorne.