By Light Rail
The light rail (http://www.metrotransport...) is ideal to access the Exhibition Centre, Convention Centre, Star City Casino or the Fish Markets.
You can catch it from its starting point at Central station. or catch in on route at Capitol Square or Paddy's Markets in Haymarket.
If you are going to Cockle Bay, the aquarium, or King St Wharf on the eastern side of Darling Harbour from the City, the light rail will take you further away from where you want to be. It will drop you the other western side of Harbourside, and you will have to walk back. Walk, or take the monorail instead.
There is level access at all light rail stations.
By Monorail
Catch the Sydney Monorail (http://www.metrotransport...) near Town Hall station and get off at Darling Park, Convention, Harbourside or Powerhouse Museum. Services are frequent and the cost of a single trip $5 is probably less than a taxi fare for one person. Think of it as ride more than a utilitarian form of transport. Family day-passes cost $23.00.
There are lifts to all monorail stations, and access to the monorail is completely flat with a very small gap between the car and the platform.
By ship
If you are travelling from Circular Quay you have an option of the Sydney Ferries (http://www.131500.info), the government owned standard green ferries, or the Matilda Rocket ferries (http://www.matilda.com.au...)$file/City%20Loop%20Effective%20October%202007.pdf.
Sydney Ferries depart Circular Quay wharf 5. They accept Multi tickets, or a single ticket will cost $5.30. They stop at Darling Harbour King St Wharf 3 on the eastern side, and at Pyrmont Bay Wharf at the very northern tip on the western side, past the Maritime Museum. Ferries depart approximately every twenty minutes, and run from 6:45AM to 10PM M-F, and 8AM to 10:15PM on weekends and public holidays. (http://www.sydneyferries....)
Matilda Rocket departs from the Harbour Master's Steps on the west left of Circular Quay. They arrive just by the Aquarium very close to the Pyrmont Bridge, at a different wharf to the Sydney Ferries. They charge $5.70 for a single ticket and issue their own tickets. They don't accept the Multi but do issue their own day passes, just for their ferries. The frequency varies, depending on demand. They run at least every hour from 10AM until 5PM.
The ferry trip takes 25 minutes or so, as the route isn't that direct by water. The ferries all need to pass under the Harbour Bridge to get to Darling Harbour. The white ticket booth at Circular Quay is selling tickets for the Matilda Rocket. Go to wharf 5 directly if you want the Sydney Ferries ferry.
The river Ferries arrive and depart about every hour at Darling Harbour King St Wharf 3, heading upriver towards Sydney Olympic Park and Parramatta.
Again, if your interest in getting in is purely utilitarian, it may be quicker to walk. To get from Circular Quay to Darling Harbour by ferry can easily take 50 minutes if you just miss a ferry. By comparison it is only around 30-40 minutes to walk there. However if you need an reason to take to the harbour on a ferry, then this is the perfect excuse!
By train
Catch Cityrail (http://cityrail.info) to Central or Town Hall stations. From Town Hall follow the Darling Harbour signs out of the station. Walk downhill west for two blocks to the eastern edge of Darling Harbour. From Central walk up into Haymarket Chinatown and then walk west to the south end of the Darling Harbour district.
Walk
Darling Harbour is within walking distance of most points in the Sydney CBD.
From the Pitt St Mall: From the northern side, walk west down King St until you come to King St Wharf and the Darling Harbour footway. From the southern side, walk west down Market St following the monorail track overhead to the Pyrmont Bridge.
From Town Hall walk downhill west. Follow the signs from Town Hall Station and the Kent St Arcade.
From Chinatown and central station walk west downhill past Paddy's Markets and the Entertainment Centre into south Darling Harbour.
From Pyrmont or Star City just keep the water on your left past the Maritime Museum.
There are a number of access methods to Darling Harbour that have steps, but a level alternative route is signposted, or an alternative lift is provided. The Darling Harbour access at the west of Market Street has level access with a lift at the eastern end of Pyrmont Bridge providing access to the bridge and water level.
By bus
If you have a Sydney Explorer pass, the red Sydney Explorer buses have several stops around Darling Harbour, stopping on the roadside of the Maritime Museum, and at the transport interchange between Harbourside and the Convention Centre, and by the side of IMAX.
The 443 bus from Circular Quay and George St goes to the Star City Casino, and the Maritime Museum lower level road. It doesn't stop at the Darling Harbour stops at the Sydney Explorer.
By car
Darling Harbour is accessible by car:
From the north cross the Harbour Bridge and head west onto the Western Distributor and then take the exit to Darling Harbour.
From the city, head down Market St west, and follow the signs and exit at Darling Harbour.
From the east or south of the City, consider the Cross City Tunnel toll applies, and follow the signs.
Like the City, parking in Darling Harbour is expensive but a number of parking stations are available. Expect to pay up to $30 for a day of parking. Some cheaper parking options are around near the Ultimo end of Darling Harbour, for around $15.