Manly is a beach resort town located across the harbour at a distance of 12km from the Sydney city centre. It's not as famous as Bondi Beach, but apparently it's much quieter. I have never been to Bondi Beach, so I can't compare. Basically it is not much more than a suburb of Sydney, with around 35000 inhabitants.
But the town has got more to offer than only a commuter's accommodation. Manly's city centre is located on a peninsula, with the Sydney Harbour on the west side of the town and the Pacific Ocean on the east side. The Manly beach, located at the Pacific Ocean is a decent sand strip great for sunbathing or swimming in the sea. As this is one of the most famous beach towns in the Sydney area, there are of course lots of bars, restaurants, souvenir shops, etc.
We did a day trip to Manly from Sydney. In the morning we took a half an hour ferry ride from Circular Quay directly to Manly. It costs 6AU$ one way and runs the whole day. From the ferry you will get a beautiful view on Sydney's CBD, the Opera House and the Harbour Bridge. You arrive at the Manly wharf, and from there we walked through the town to end at the Manly beach. In this part of town there are many shops and bars. From all parts of Manly you can make many beautiful walking trails. From Manly beach we did the 30 min Fairfax walk on the peninsula in the south of the town, ending at the wharf.
We continued our walk past the wharf for 1 hour (part of the Manly scenic walkway) to end in Dobroyd Head where you can find a nice secluded beach, some beautiful scenery and a beautiful view on the Sydney skyline. You can walk further along the scenic walkway to Sydney, but we decided to take a bus back to the city centre, because it was still a 2 hour walk!