My small pc - RASPBERRY PI

Logins
Default username = pi
Password = raspberry

To become root
sudo su -

To start desktop x-window
startx

Shutdown
sudo shutdown -h now

List of installed packages/application
sudo aptitude

Play MP3/Videos
omxplayer mysong.mp3
or
omxplayer -o hdmi myvideo.mp4  (for output of sound via hdmi cable)

Install packages/applications
>require internet connection

sudo apt-get install <packagename>
Example : sudo apt-get install tightvncserver

Setup apt-get to use proxy internet connection
create file "/etc/apt/apt.conf" and type below. Watch for ';' at end of line
Acquire::http::Proxy "http://your-proxy-server:portnumber";