I have attempted to install Debian onto an Apple Mac 4400. According to the installer I have done so succesfully. All I am presented with on startup after log in is a black screen with a prompt like a dollar sign. I foolishly imagined ( after all I am only a Mac user) that some sort of GUI would appear automatically. What on earth should I do. Installing was a nightmare, I have no idea if it was done correctly. I would be grateful for any help.