I have a cellar full of computer gear that runs my house and this website. On this bit of my site you'll find notes and tips on how to keep it all working. This is mostly reference material for me to look back on, but might also be useful to other people.
Send all portscan and scripted bot attacks to 127.0.0.1, thanks. You're not going to be learning that kind of hacking here.
A combination of simple file permissions and umask settings will allow you to share a folder amongst users, and yet have the folder and its contents owned by a common group. Everyone can read/write/modify, and files aren't owned by any specific user's group.