Using you mouse maneuver the map to the correct area (left click and drag your mouse).
You can zoom in or out of the map by using the + and - slider on the left side of the map. You can also use your mouse wheel to zoom.
Once you have the map in the correct place, left click on the start point for the boundary of your survey area.
Then simply click along the boundary of the area until you have a pink block covering the site.
When you have finished selecting your area of interest, click on the 'Get Custom area list' button below to create the species list