I am trying to set up a VNC server, I don't really care which one it is as long as it's sort of secure, and free. I would like to configure it so it acts like Windows Remote Desktop, and presents the user with a login screen, like Gnome's or something, that lets you log into any user, and preferably show it again when you log back in over VNC but still keep your programs running, like Remote Desktop. I would also like it to start automatically when the computer starts up. Is there any way to do this?
Btw, I'm not great with Linux so detailed instructions would be greatly appreciated.