Terminal

After Installing Ubuntu, you are mainly going to work through Terminal, therefore I will discuss about basic commands in Terminal.
First of all, in order to open a new terminal, you can go to dash home at the top of the side bar at the left of your screen and type terminal and then click on it or you can click Ctrl+Alt+T
After you opened a terminal, you can check the current working directory by typing pwd. 
 In order to see what files and folders are in this directory type ls. Remember that there might be some options for the command that you are typing, you can read about these options through manual pages, e.g. type man ls. You are able to move up and down in the manual by Up and Down arrows of your keyboard and you can search by typing the favorable text after slash e.g. /full. You can quit the manual by typing q.

installing Ubuntu

In order to install Ubuntu, please visit this website
After you are directed to the website, click on Ubuntu Desktop, and it will get you to the download page for the latest version of Ubuntu (12.04) which I believe is still the Beta version.
I believe that it is better to download Ubuntu 10.4 instead of 12.04.
Anyways, just follow the instructions on the Ubuntu web page, and remember that it is possible to have Ubuntu alongside your other OS.

ubuntu

I am going to write a few posts about Ubuntu, which is a free open source operating system and there are a wide variety of open source applications and softwares available for this OS, e.g. GNU compilers, tcl tk. With the help of these softwares we can provide ourselves with more comprehensive tools for programming.
I start with beginner lessons and move forward to more advanced topics towards programming in C, fortran, tcl tk, Octave and etc.