The best program that I know of is
Backer. It's shareware, and you can download a trial version at
http://www.cordes-dev.de/english/trialversion.html. The latest version is 6.3.
It features the ability to schedule backups and drives can also be synchronized. You have the option of previewing the files and folders to be synchronized so that you can select what is to be copied (in either direction) and what is to be skipped, or deleted. It can be totally automated too, if you wish, to simplify the daily routine.
You can also link a wav file (wav's included) to an event so that a nice friendly female voice will prompt you when something's done! I am not an employee of Cordes Development, but I can vouch for this application.
Best of all, it's really simple to use, and does not take up much disk real-estate.
Better than using DOS (which is almost dead) and fiddling with switches. Sometimes using a DOS switch wrongly could result in a disaster.