Backup your critical files. This is one of those tasks that can be overwhelming the first time you try to do it. The first step in backing up your critical files is determining what is critical. If your files are organized neatly in your My Documents folder, then simply backup your My Documents folder and you are done. If you have files scattered in various folders on various devices, CDs, thumbdrives, external hard drives, etc. then you have a lot of work cut out for you. For the unorganized, the first step would be to organize your files. I would highly recommend either using the My Documents folder which already has a My Pictures, My Music, and My Video sub-folders or create a My Documents like location where you can move all of your files to. Once your files are located or re-located, fire up the backup utility in Windows and place a check mark next to the folders containing the precious files. Next, select where you would like the backup to go. It would be ideal to back them up onto a external storage device and them put that device some place safe and not at the same location as your computer(s). A relatives house or the drawer in your desk at work or even a safe deposit box would be better than keeping it at your house right next to the computer. Another backup location could be an online solution like Carbonite. The important point to be made here is to have at least 2 copies of anything you do not want to lose forever (pictures, documents, home movies and videos, etc.).
Link: http://www.carbonite.com/
Next: Tip #8: Perform regular maintenance using tips 1-7.