this is something we have worked on for several years and have not found a good solution
1745 has used shared drives on the schools network ( the R drive), google docs, a Joomla module called docman with a lot of modification to sync with our google docs, and 2.5 in usb hard drives. the problem with each of these is allowing documents to be easily shared with all the members regardless of location became a huge hassle( with the joomla mod we had to add each member for each file and re add them each time someone made changes . . it got to be a major pain).
Now we use something called Dropbox.
https://www.getdropbox.com/ . It syncs well with all operating systems, it works on personal computers as well as the school computers, it has very low overhead, and doesn't require for you to be connected to the Internet to make changes to files as it stores every thing locally. unfortunately it offers no user or version control by itself( we have a pearcerobotics account that every one syncs to so I as a lead Mentor have the same rights as a freshman student, and I cant tell who changes what).
so far Dropbox is the best we have come up with, but it is far from perfect. we are currently looking at modifying the previous docman/google doc system adding in GIT/SVN and linux user/group controls on top of the whole thing. . . but thats a summer type project.