While it's relatively easy to know what ballpark you're in for flat screen gaming, knowing whether your PC will be able to handle one VR title to the next is a little more complicated. Of course, it's always best to check the system requirements of any game you're thinking of buying: they can be found at the bottom of a given title's Steam page. I would recommend brushing up on your PC parts knowledge before buying a headset. It pays to learn about RAM, CPUs, and GPUs to ensure your PC (or one you're going to buy) is up to scratch for each title you want to play. The best resource I've found is the sidebar in the Build a PC subreddit. Further to that, the VR Gaming subreddit also has an extensive information page.