File sharing for non-tech savvy non-Profit?

I am involved in a non-profit charity/service orginization with ~30 members. Most of the members have very little computer experience, it's a 70+ crowd. Currently they share things like meeting minutes, budget reports, and other documents via email. Does anyone have experience migrating a group like this to something cloud based (Dropbox, Box, whatever)? If so, what was the easiest to get up and running as well as get the users to adopt it?