can't login as root
 

i'm running ubuntu linux. when installing, i was asked for a user name and password which i gave. now, when the login screen comes up i can use the username and password that i entered during installation, but i can't login as root or as SU. what's going on? when i type "su" in the shell, it askes me for a password. i've tried using the username and the password that i entered during installation and they both don't work.

Ubuntu uses sudo by default. Read this for info about enabling the root account.

thanks, got it now. is there a special how to guide written for Ubuntu? i checked ubuntuforums.org but the guide isn't what i'm really looking for. i'm especially interested in the commands in the shell. also on unpacking/zipping apps and installing them.

I don't know what's on ubuntuforums.org, but maybe take a look at this and this? For installing stuff, the easiest thing to do is use your distro's package manager, which for Ubuntu is APT.