Airport extreme security choices?

[Jack Countryman]

In setting up an airport extreme base station, I find several different
choices under security.  These apparently refer to different encryption
methods.  However, I have no idea what the differences are, which are best
or best for what situations, etc.  The manual with the base station doesn't
cover this that I can find.  What is the best/strongest choice, or what do
folks usually use?  Is there information on these settings available
somewhere?