By train
CityRail (http://www.cityrail.info) runs three train lines into Sydney's North West.
Trains on the Northern Line connect the city to suburbs as far south as Meadowbank on the northern side of the Parramatta River, up to Epping, Pennant Hills and Hornsby in the North of Sydney, with trains every half hour and more frequently in peak hours. The suburbs of Eastwood and Epping are also served by regular intercity trains on the Newcastle and Central Coast Line which connect Newcastle and the Central Coast with Sydney.
The suburbs of Carlingford, Telopea and Dundas in the west of the Northern Districts are served by the Carlingford Line. Carlingford Line trains do not run directly to and from the city. To get to these suburbs, take a Western Line train to Clyde and change to platform 1. Note that Carlingford Line trains only run once an hour.
The Macquarie Park and North Ryde area is served by a shuttle train service running between Chatswood and Epping, and also stopping at North Ryde the stop for Lane Cove River Tourist Park Macquarie Park, and Macquarie Universitythe stop for Macquarie Shopping Centre.
There is no train service out further. To access the residential areas of Baulkham Hills, Castle Hill, and further afield, you will need to catch a bus from Pennant Hills Station, or Parramatta station.
By bus
Buses from the citydeparting from the Queen Victoria Building near Town Hall train station also departing from wynyard station and central station travel frequently out to Macquarie Park, Epping, and the Macquarie Shopping Centre. The 545 bus also travels between Chatswood train station and Parramatta on a very regular basis.
Outer areas such as the Hills District are less well serviced. except for all the city buses. 610 610x 612 612x 619 etc etc. but other than that there arent many ways to get to the exact same place.in fact short of 4am you can get a bus from the centre of the cbd to the middle of the hills area about 1 every 10 minutes The most convenient railway station for the is located at Pennant Hills, however, in general, it's much more convenient to have your own car for traveling around the area. Hillsbus (http://www.hillsbus.com.au)] services the area. It runs connecting buses to stations at Paramatta, Seven Hills, Pennant Hills. It also runs services directly to the Sydney City.
The transport infoline (http://www.131500.info) will calculate the end-to-end trip details for you.