One trick a graphic artist showed me is that if you want double lines for
streets (so that you can put the street name between the lines), draw a line
for the street (straight or curved), duplicate it, increase the line weight
of one of the lines, superimpose the lighter line over the heavier one
(centered), and change the line color of the top one to white. The part of
the underlying black line that extends to either side of the white line will
make it look like a double line. If you want your streets to have 1-point
line "borders," make the weight of the black line 2-points more than the
weight of the white line.
Unless you're very skilled at freehand drawing, however, creating anything
more than the simplest map this way is very tedious, and Word is definitely
not the best program for doing it. If you have Streets & Trips, MapPoint, or
another mapping application from which you can copy or export maps, you'll
be better off using those.