TkSurfer can be started in any of three ways: launching it from FreeSurfer with the Surface button, using the tksurfer-sess script, and calling it from the command line. Depending on which method you use, you may see different types of data loaded, but all methods require a surface data set to be loaded. Other types of data can be loaded from the File menu.
The simplest way to start TkSurfer is with the following format:
tksurfer SUBJECT HEMISPHERE SURFACE
tksurfer bert rh pial
Where SUBJECT_NAME is the name of a subject in your subjects directory, defined by the envrionment variable SUBJECTS_DIR, HEMISPHERE is lh or rh, and SURFACE is the name of a surface in that subject's surf directory, such as pial, white, inflated, sphere and so on. TkSurfer will concatenate the HEMISPHERE and SURFACE parameters as HEMISPHERE.SURFACE and look for that file to load.
To explore your data, you can move the mouse over the picture of the surface (the Display Window) and see information about the area under the mouse in the window on the bottom (under the Mouse section of the TkSurfer Tools Window). You can change the view with the navigation buttons (under the toolbar, with icons of various arrows). These buttons will rotate and translate the brain.
To save pictures of your data, go to the Tools menu and select the Save TIFF As... item near the bottom.
By default, TkSurfer does not redraw the display window unless you perform a command that changes the view. This means that if another window obscures the display window and then is moved, the display window will not automatically update. This because of the time it takes to redraw an average surface. To explicitly redraw the view, just click on the Redraw button. If your display card seems to be fast enough to draw the Display window without a problem, you may enable automatic redraws with the View->Auto-redraw option.