NO, DO NOT run what it says on the side of the tire! That's the MAXIMUM inflation under maximum load, not the regular everyday running pressure. Read the fine print in front of that "xxPSI". Just thought I'd point that out.
For mine, it's 35/41 (front/rear) for 235 tires, but the 41 is bogus. I like to overinflate my tires slighty, so I normally run in the 36/36 to 39/39 range. You shouldn't go under 32/32, or over 41/41, except if you tow something heavy.
OK here is the best way to do it. Have all the normal everyday things in your bronco.
Then take a piece of chaulk.
Draw a straight line across your tire.
Drive about 20' perfectly straight
check the line, see where its worn
edges= add more air
middle= take away a few LBS
try to be as close to even wear as possible. Also keep in mind that if you have any camber issues and you use the front tires (that have been there for a while) this may mess your reading up a bit as one edge may be severly worn.