If you are old enough to remember wearing a
mechanical wind-up wrist watch, you know that you
simply wind the stem each day, and pull the stem out to
set the watch (actually if you wear a modern analog
quartz watch, the setting is the same).

There are various acronyms and abbreviations
regarding the setting and winding function of a pocket
watch.  Well, here is a concise list of these functions
and brief "How To":

Stem Set (SS): This is the most well know. You
simply pull the stem out and turn to set the hands.  
Sometimes the stem is a little stubborn to get out on an
older watch, due to corrosion and the like.  But before
you pull to hard, make sure that the watch is not a lever

Lever Set (LS): On a watch with a lever set, you
have to remove the front bezel (the part with the glass)
by unscrewing, or opening on a hinge.  When you have
this open, there should be a small groove with the end
of the lever that can be gently pulled out with your
finger nail. Be cautious not to bend or break the lever
off, as it can be fragile. After the lever is out, you can
use the crown to set the hands.  After complete, simply
push the lever back in.

Setting and Winding
antique watches

Key Set (KS): For this older design, you simply have
a key that is mated to a square arbor on in the middle
of the dial on the hands, and turn the hands directly.
Again, you have to remove the front bezel.

Stem Wind (SW): Simply wind the stem until
resistance is felt. Some watches can be harder to wind
than others.

Key Wind (KW):Using the same key as setting, you
open the back of the watch (there is usually an inner
casing, and put the key on the square arbor and wind
until resistance is felt).