On the left side of the LINK-GIS map viewer, there are navigation controls. These tools appear washed out when not in use. However when you pause the mouse over them, they will become darker.
Starting at the 
top, there are + and – buttons to zoom in to and out from the center of the map. The next button down, that looks like a house, is the Default extent button. Clicking the Default extent button will return you to the inital extent of the map, when it is first loaded.
Below the Defualt extent button is the Find my location button. Clicking on the Find my location button uses your current location to find the location on the map. This may require allowing your web browser to share your location or turn on location services. If your location is shared, the map veiwer will zoom to your location and place a blue dot where it thinks you are located.
To pan around the map, simply click on the map then drag the map to a new position. The farthest the map will zoom out is a scale of 1:480,000 and the farthest the map will zoom in is 1:600.