There is a police station and first aid station at the tip of the harbour. The area is quite well patrolled, and generally busy, and it is a comfortable area to walk in the daytime and into the evening.
Late on a Friday or Saturday night there is drunken behaviour. After 10PM or so on a weeknight the area can get quiet, if there are no events on that night.
There is no fence around the harbour, and the water is deep. Watch young children don't fall in. Ladders are located at regular intervals, and life rings are scattered around as well.
contact
There are coin operated internet access terminals on the ground floor of Harbourside. There are public phones distributed about the precinct.
If you are attending a convention, ask you conference organisers about Wi-Fi access in the convention centre.
There is a McDonalds restaurant in Harbourside, with a free Wi-Fi hotspot that covers a section of the food hall. Really easy to use without buying any food there.
Sydney Visitor's Centre is the information centre that can assist in providing directions as well as booking tours, accommodation, attractions and much more. Operated by Best of New South Wales.
cope
Toilets are located under the Pyrmont Bridge on the eastern side, next to first aid, in Harbourside and Cockle Bay Wharf, and next to the curtain fountain at the southern end precinct. They are available at several other locations as well. Baby change facilities are available there too.