Spatial selection is easily handled with the mouse keys.
Typically, when the map form is loaded the first time, it shows a default selection layer and the available point layer. The user has typically the option to switch between Select Area and Select Point.
By default, the select button is activated ("pressed"), if not, it can be activated by clicking once.
The following options are available for spatial selection:
click individually on each spatial item, by holding the Shift-key.
You can either select within the top area layer or the top point layer, depending on the chosen option.
Multiple selection of areas
by holding the left-mouse key and dragging the cursor:
this will result in the selection of all areas (polygons) touched by the rectangle you are drawing.
Multiple selection of points
by holding the right-mouse key and dragging the cursor:
this will result in the selection of all points inside of the rectangle you are drawing.
In addition to spatial selection, you can select / deselect records in the corresponding GIS data table.
Navigation in the map (zoom in, zoom out, pan) is managed by the appropriate buttons.