Our School made a fieldtrip to Cronulla beach.
You will probably need to be able to describe how you have collected primary and secondary data from your area of choice. We took temperature, humidity, water temperature samples, made observations on the environment, took information from reports on the area, threw a cork into the beach to observe longshore drift, etc.
We mainly focused on observing the issues that were impacting the coastal environment and the role of Government and NGOs in combatting these issues.
Cronulla Beach is an area mainly focused on tourism, and so the council has the responsibility of providing facilities for tourists, but also making sure that this does not impact on how the site is used by other people, such as residents, environmentalists, etc.
One major issue at Cronulla Beach is the erosion of sand dunes and the beach, the impact of this issue is that it discourages tourism in the area, due to the Sutherland Shire council's dependance on the area for money, they have devised strategies to combat this issue. In 1974, after huge storms washed away most of the sand/sandunes on the beach, the council constructed a very expensive "seabee wall" to absorb the impact of high energy waves and to decrease the amounts of sand washed out to sea. Other strategies include the replenishment of the sand or "beach nourishment programs" in the area by simply dumping large piles on the beach every few months. These strategies each have implications - they destroy the visual amenity of the area, they cost money, they affect the environments the sand is taken from, etc. Other strategies to protect the sandunes include the planting of vegetation over the dunes, the construction of silt fences, and the construction of pathways to prevent human interference, etc. There are so many other things that you can discuss.
The main thing with the fieldwork aspect of Geography is to have knowledge of a certain physical environment, the problems that impact that environment, the role of Government and NGO in finding solutions to problems in the environment and the implications of their choices to other aspects of the environment. Think Tourism/Ecosystem/Agriculture/etc. I hope this has helped in someway, and I only wish I could give you more information, but there's just too much to discuss in Geography.
These sites may be of some help, but if your class hasn't studied coastal environments, then you would probably be better off doing a RAP, etc on an environment related to that field.
http://www.skwirk.com.au/p-c_s-16_u-140_t-414_c-1451/coastal-management/nsw/geography/issues-in-australian-environments/geographical-issues-physical-environments
http://www.sutherland.nsw.gov.au/ssc/home.nsf
Good Luck!