You might want to check out freelance sites such as guru.com or elance.com. See if you can find others with similar sites and perhaps find information related to fees. That could be a good way to find out what others with similar skill sets are charging.
You might also want to do a search on your skill set on Dice.com and other technology job sites. That might tip you off to what kinds of related things employers are looking for right now. It might also give you some job possibilities to consider.