Word does not have the built-in ability to print double-sided. Some printers
have this ability; if you have one of these printers, you can choose the
double-sided option in File | Print | Properties. If your printer doesn't
have a duplexer, you can print the odd-numbered pages, put it back into the
printer's input tray, and print the even-numbered pages. If the total number
of pages is odd, then remove the last odd-numbered page from the stack before
putting it back into the printer to print the even-numbered pages. Depending
on whether your printer stacks output face-up or face-down, and whether your
printer prints on the top or bottom side of the page in the paper tray, you
might have to print the even-numbered pages in reverse order.