It pays here to do some research. If you can find out who volunteers regularly at the non-profit, find out about the place from them.

For instance, my local hospital runs a volunteer League of Friends who perform regular fundraising drives for equipment such as neonatal equipment, scanners and so on. The League has an iron-clad reputation, and listing on your cv that you have done volunteer work for them actually counts as a mark of honour when applying for local jobs.