Many individuals are struck by the Xbox 360's Red Ring of Death. Hopefully you haven't been at least one. There are several things that you can do keep your Xbox running as smoothly as it can be.

Ventilation
Heat is a killer for any sort of unit with electronic components, dark age limit; Recommended Resource site, your Xbox included. Due to that it is really important to make certain the Xbox of yours has space to breathe. Don't include some other heat creating products such as a DVD player next to the Xbox of yours.
If you have your Xbox tuck neatly out of sight in a closed in spot, rethink the placement of yours. Once again, your Xbox needs air flow to help keep it cool. Also, do not place anything, electronic or otherwise, on top of or under your Xbox. It needs to be free standing with airflow to keep the electronics from overheating.

Make sure you keep It in Perspective
Simply since your buddy's Xbox died once the white lights came on does not mean yours will. If you get red lights showing, understand that different lights in various quadrants mean things which are different.

A red light could suggest an AV cord is loose or that the system simply should be reset, not necessarily you are going to have to send in the Xbox of yours for maintenance or change it completely. Your owner's manual or a call to customer support will get you a great deal of information.

Watch the Warning Signs