Here’s a video I prepared that shows you how to mailmerge using OpenOffice applications. Mailmerge is merging a database with a form letter, so you compose one form letter but, when you print it, it prints out several copies, each with a different addressee so it looks like you personally wrote that addressee. Mailmerging saves you time and effort so it increases productivity.
OpenOffice is open source software that you can download for free at OpenOffice.org.
By the way, the video was made using XVidCap, also open source, which you can download at xvidcap.sourceforge.com.