There are a number of methods. The first is just what you mentioned, write your name on a piece of paper, scan it into your PC as a
graphic (if you don't have a graphics program you can use http://www.irfanview.com ) and then in Word use Insert=>Picture to place
it in documents when needed or store it as an Autotext entry in Word.
Another is to create a font version from your signature, from a site such as http://www.fontifier.com or if you're just looking to
have a cursive signature, rather than a true copy of your own there are sites that have signature graphics such as