Hi,
I think there is a genuine lack of documentation for ART, unfortunately. Things are getting better, thanks also to the contributions of users (e.g. @BarryThomas recently added a “quick start” guide), but writing good docs takes a lot of time.
Regarding exposure/brightness adjustments, here’s a description of how to emulate a tone curve with the Color Correction module:
EDIT: in addition to what written above, if you want a simple exposure compensation, that can be done with the “slope/highlights” slider in the color correction module, which does exactly the same thing, except that the scale in the GUI is linear, instead of being logarithmic like in the exposure module (therefore, to add e.g. 1EV of compensation, set “slope” to 2).
I probably need to find some time to turn this into a proper wiki page – it seems many people struggle with this…
Hope this helps