Here is a good resource.http://ubuntuguide.org/
I am a newb to ubuntu and this answered most of my questions.
I used to hate sudo, but I have a real bad habit of doing too much as root.
Sudo helps only be root when you need to be.
To install from command line you only need to open a terminal and:
sudo apt-get install <name of package>
enter password for sudo.(same as your login.)