Yes you'll have to know them first (mostly from experience, from tuts or from word-to-mouth) then google them.
Some are free, some are not. Pretty much like anything that CD-player in your car or the hands-free phone system,
these were not built-in by the constructor you added them to augment your car.
The software business has a little bit of the razor-blades model in it, so it's yours to go and buy the extras and make sure to update them
You can google "vst plugins for audition CS5" and go from there as a starting point. Explore and discover.