Ya smart decision to take public transport in HK.

Buy a optoplus card (smart card) in airport metro station and preload with 500bugs can get you hassle free travel for Underground and Buses, Ferries, 7-11 shops etc.

Underground is affordable, accessible to all major destination, but not complicated as NY and London tube.

Old style HK Tram is a must try, but don't do it in mid day cos it will feel like taking train in India.

Ferries across the harbour is another public transport but more on the tourist side. Do this in the day time for photo

Take the Peak-tram from Admirarty to go Peak and come down by Bus can give you all the views of HKIsland. Do it in the evening.

Logon to KMB.com or Citybus.com.hk for detail bus route & fare.

Have fun in HK> I am going home (HK) at Eid holiday as well.