how to prep a new bouldering area

the new bouldering area i have been climbing is a few large boulders stacked on top of each other. there are allot of loose rocks and spiderwebs. my question is what kind of preparation can i do to the routes without oh i don't know be accused of cheating or destroying the environment.i have seen guys use tooth brushes to clean off the dust in holds how much is to much

I take a slightly different approach. First, for all but the chossiest rock, heavy, non-metal brushes should be fine. I say non-metal because you don't want to score the rock, and depending on how soft it is, you could actually be shaping holds. Which is not cool.
As far as heavier stuff- gravel, loose flakes, and the like- try to only remove what would come off naturally (given say 100 ascents). The idea is that you must be willing to accept the rock for what it is. It may not seem like it, when you are deciding whether to reinforce a flake, or rip off a flake, but it is always better to accede to nature. Hammer,, screwdriver, pry bar can all be useful in this process. It's a balance. Go into it with the best of intentions, and be openly communicative about your thoughts and choices, and most climbers are likely to respect your development.
Finally, try to only remove the vegetation that actually has to go. Vegetation, out of the line of the holds on the boulders is beautifying and helps make for the non-gym experience that is sp integral to our sport. See Magic Wood.

+1 ^

Just take this into consideration. Rocks move downhill...

en.wikipedia.org/wiki/Erosion

Unless your personal safety is at risk, just climb the stuff and whatever comes off comes off. If you need to pry of a flake because it's gonna land on something alive, that's probably ok.

I don't know where this is, but as long as you leave the area in good shape your ok... look what they did to Mt. Rushmore, or sphinx crack.