How do you crush blacks in vegas? Should I use the gamma settings, or is there a better way?

gamma settings?
do u mean curves?

there are many presets available to download, however curves are what your looking for if u want to crush blacks and blow out the whites

Yes, gamma curves. Where do I find them in vegas?

Color Curves editor under FX.

For a simple tool, there is also the black restore filter (stock Vegas filter).

The black restore filter does something else. You probably want to be using color curves.

These curve presets may be useful for studio RGB levels (the default DV and HDV codecs decode to studio RGB levels):
http://glennchan.info/Proofs/forums/sony%20back/curves-and-secondary-presets2.veg

You can do basic gamma work (and crush noisy blacks to flat zero) with levels, as well.

It's a very easy filter to use.