How do I know how many points are half an inch?
One inch is 72 points, so a half inch is 36 points.
In Word's dialogs where you enter measurements, you can enter most of them with
the abbreviation for any of the recognized units (in or ", cm, mm, pt or pi for
inches, centimeters, millimeters, points, or picas) and they'll automatically be
converted to the standard unit for that dialog. (Some of the "standard" units
depend on the setting of the measurement units in Tools > Options > General.)
For example, in the paragraph format dialog, you could enter the Space Before
measurement as 0.5". After you click OK, if you open that dialog again, it will
say 36 pt.
The only exception I know of is the point size in the font dialog, which accepts
only a number in points.