Originally posted by cybergoober
Your best bet is going to be Share Points (search versiontracker.com/macosx). This will allow you to share individual folders or drives. In OS X, by default, you can't share individual folders or drives. When you enable sharing you share each user's home directory. Logging in as Guest gives you access to each local user's Public folder. Logging in as an admin user gives you full access to the system, all local drives (except other users' home directories). Logging in as a normal user gives you access to that user's home directory and all Public folders on the system. All of this applies to logging in using Apple File Protocol. When logging in from windows you are presented with whomever's home directory you log in as.