Adam has published a simple and awesome list:
Itâ€™s no secret that tech-savvy computer users typically become the go-to guy for all technical help in their circles. More specifically, Mom and Dad tend to always ask us for help with their computers. If youâ€™re tired of the phone calls from Mom and Dad complaining on how sloooww their computer has become, how fast it used to be, how many pop-ups there are, etc., spending hours upon hours fixing and repairing, re-installing and scanning, then this post should convince you with 5 reasons why your parents should use Linux.
=> 5 Reasons your parents should use Linux (foogazi.com)