Web Sharing Home Directories

First of all, I have been perusing this site for awhile as it's helped me troubleshoot. It's GREAT! I work in a public high school of about 1000 students and staff. I would like to make available users' home directories over the Internet so the user could login to pick up or save their work from their home computer (Mac or PC). It would have to be secure, of course! What do you recommend as the best way of doing this? Should I use FTP? WebDAV? I'm kind of stumped by the right approach. Any one doing this ...or... does anyone have any recommendations?