First off create a new doocument whatever size you want, depending on what your using your text for. I'm using something like 320x100. Go ahead and write the text you want (doesn't matter what color because we will change it later. Also this tutorial works best with thick fonts, I'm using the font called "Army" and you can get it at http://www.dafont.com ).



Ok now select your text layer and go to "Layer" then "Add Vector Mask" then "Hide All." Your text should disappear....don't worry its still there, its just "invisible" for now. Now you need to select your brush tool, and find a couple good grunge brushes. If you don't have any check out these sites:
http://www.studio911design.com/brushes/psbrush/psbrushes.php
http://www.photoshoproadmap.com/Photoshop-downloads/Brushes
Ok, now you need to brush the text lightly like you would a grunge sig. Your text should start "appearing" Good, keep doing that until you have something like this:




Ok
Now apply these styles to your text, by clicking the little "F" looking thing at the bottom left corner of your layers patlett.

Stroke:


Color Overlay (feel free to use whatever color you want)


Bevel & Emboss


Inner Shadow:


And finally Drop Shadow


You should have a nice looking text like mine: