Find out what doesn't work with Linux
When Linux was in its infancy, hardware support was one of the biggest issues for the open source operating system. Good drivers for everything from video, audio, network cards, human interface devices, and the like had to be reverse engineered and written from scratch by hackers. Broader support these days by major PC hardware and peripheral manufactures has made the Linux hardware compatibility more widespread, but no one's claming "mission accomplished" on this yet. One site that maybe useful for users still struggling with Linux hardware compatibility is Leenooks.com, which maintains the "Linux Incompatibility List" - a database of hardware, ranging from audio components to Wi-Fi gear, that does not work with Linux. (This is at least according to the Web site's maintainers.)
Even the disclaimer on the Web site recognizes how far Linux hardware support has come: "Fortunately, at this point in time, there is far, far more hardware that works without any problems with Linux, so this site aims to make Linux users aware of hardware to avoid (or if you want to be famous, hardware to write free drivers for)."