EricM - Yep, you just place the CD in and boot ePSX up. Do note you may have to configure the cd drive dirver to use, the graphics drvier to use, and the sound driver to use (loads of plugins on the website, though it comes with some pre-built in), and these can all have a positive effect to how they play, and how good the games look.
Cileskot - Yeah its weird how on a computer system, you tend to only one best game that you play more than others. For instance, playstation for me was Crash Bandicoot, Sonic on Megadrive (Genesis), Snes with the original Starfox, etc