Sydney
 

Will be in Sydney 6 nights--hoping to visit the Blue Mts. Do we need a car to do the Blue Mountains and if not how do we get there? Once we get there what kinds of things should be on our must do list. While in Sydney would Manley and Bondi beach be something to see (going in October)--is one area better than the other or are they very similar and maybe only need to see one.

Blue Mountains: you can take a train & then use buses or take a small tour.

Or rent a car, which is my preference because of the flexibility & perhaps go up via the Great Western Highway & the mountain townships. Come back via Bells Line of Road, call into the Botanic Gardens at Mt Tomah.

Have a look at the Blue Mountains destination tag here and/ or google Blue Mountains Tourism.

Manly - 30 minute ferry trip. Well worthwhile - some very pleasant & interesting walks, swimming,
Art galleries, restaurants etc.
picture post card views coming back to Circular Quay, particularly late afternoon/ early evening.

Bondi Beach: take a bus or train/bus combination. Or take a bus to Coogee beach or Bronte Beach & walk to Bondi along the cliffs. Google: Coogee (or Bronte) to Bondi walk.
From Bondi, take bus to Watsons Bay, explore National Park, old Fishermen's cottages, bays & coves. Ferry back to Circular Quay.
Note: check ferry timetables for last ferry times.

If you like walking, there is a particularly nice walk from Rose Bay to Watsons Bay. Google it. 8kms, best at low tide, about 3 hrs, Nielsen Park good for a swim, meal, drink, coffee.

The question re Manly v Bondi is often asked on here. In my opinion if you have the time see both. If you have to choose, then I would see Manly in preference because you get the added bonus of the ferry ride across the harbour.

Fwiw a few tips about going to and from Bondi Beach from the Sydney CBD by bus -

to ensure a seat on buses - which can be packed in warm weather or when there's an event on - go to Circular Quay and take a 333 or 380 North Bondi bus from where they originate at stand E at the eastern end of the Quay

consider returning to the city/ Quay via route 389 from Glenayr Ave, just a few blocks behind the beach - this bus is likely to be far less crowded (and less frequent admittedly) than those picking up along the beachfront and will take you back to the city on an interesting route via swank Woollahra and the back streets of trendy Paddington

avoid going to Bondi Beach on the last day of Sculpture by the Sea! - http://www.sculpturebythesea.com/Home.aspx
(as we foolishly did a few weeks back, when knowledge of the 389 option proved particularly handy)

Thanks farrermog for the great info about getting to and from Bondi Beach--was not aware of the Sculpture by the sea and we will actually be there during that time (not on the last day though!!) so hopefully will be able to get there.