The same way that Windows users do it. Buy hardware that is supported by the operating system.
The fact that most Linux distros will install and run on most hardware is a bonus. Just like with Windows, if you want to ensure compatibility, make sure that the hardware you buy is actually supported by your distro of choice.
The same way that Windows users do it. Buy hardware that is supported by the operating system.
According to the documentation, my card is supposed to be "supported". The problem is the same one that Linux has always had - many hardware and software vendors do not write code for Linux. So while the generic drivers that came with Ubuntu would allow me to see a maximum resolution of 800x600 on my 19" monitor (default resolution of 1280x1024), that is hardly what I would consider "working". The "restricted drivers", which were supposed to allow access to hardware acceleration, etc, would give me a black screen with a white box for a mouse cursor. I downloaded the beta drivers from NVidia that were supposed to work, but the installer would fail until I took 2 GB of RAM out of the box and added some obscure, poorly documented switches to the command line.
The point is, if Linux does not provide support for the most popular and current chipsets for video and audio, it is a severely limiting factor for most casual users. Most home users still want the Plug-and-Play convenience, and in my opinion, Linux still lacks in this area.