Hi Kelly,
I would recommend the photo editing program ULEAD Photoimpact 12, by far the most advanced & versatle editing program available. When in the field, I provide the best lighting environment that I can with what is readily available (positioned reflectors ect) to have as evenly lit and balanced field of view that I can, that is all you can do. Dont worry about anything else beyond that point, complete your shoot.
Digital imaging recording equipment such as camera's & scanners are nothing more than pixel arranging & altering devices. If your subject has a brighter or darker side than desired simply select that group of pixels to be altered and in a matter of a few minutes edification with Ulead PhotoImpact12 you problem is solved. There are several editing programs available but Ulead is by far the best. It wll take a little time to become familiar with the program but it is time well spent.
Ulead Introduces PhotoImpact 12, Latest Version of Acclaimed Image Editing Software
eventdv.net: Ulead Introduces PhotoImpact 12, Latest Version of Acclaimed Image Editing Software