Not necessarily for July, but I used to create a "challenge" every month for my guild (which I preferred to call an "exploration"), and I've kept a list of them on one page at my website if you want to check them out... there are also theme ideas which have been suggested elsewhere online and by others for my guild, as well as discussions about what "explorations" like that actually involve:
Exploration Themes:
http://www.glassattic.com/polymer/EXPLORATIONS.htm
Diane B.