Debian GNU/Linux

Configuring the system 

Disk partitioning

Recommended Partitioning Scheme: "For new users, personal Debian boxes, home systems, and other single-user setups, a single / partition (plus swap) is probably the easiest, simplest way to go."  [...] " For multi-user systems or systems with lots of disk space, it's best to put /usr, /var, /tmp, and /home each on their own partitions separate from the / partition."

Keyboard layout

I use a laptop with a Finnish keyboard and a docking station with a French keyboard. I chose the "SHIFT+ caps lock" keys to change from one keyboard layout to the other. By default the French keyboad has a comma as decimal separator on the numeric keypad. I changed this under:

 system settings / region and language / layouts / French / Options / Numeric keypad delete key behaviour / 4 level key with dot

Installing programs

Package management with apt-get or aptitude. Aptitude is recommended. Here is a comparison in a forum.

Programming

Install a version tracking system

sudo aptitude install git

Add coloration:

git config --global color.ui true

Install the vim text editor

sudo aptitude install vim

Edit the vim configuration file:

vim ~/.vimrc

In this file add:

syntax on
set tabstop=4
set expandtab
set softtabstop=4
set shiftwidth=4
filetype indent on

au BufNewFile,BufRead *.md set filetype=txt

Non-Free (unfortunately)

Skype on Debian wiki (for 64 architecture) try alternatives Ekiga and Linphone (Linphone use with French ISP free). Load skype for Debian from the website, then:

sudo dpkg --add-architecture i386
sudo apt-get update 

sudo dpkg -i skype-install_file_you_downloaded.deb 
sudo apt-get -f install

Adobe Flash

sudo apt-get install flashplugin-nonfree
sudo update-flashplugin-nonfree --install

Super user

As a super user install the program called "sudo" :

apt-get install sudo

how to-properly-configure-sudoers-file-on-debian-wheezy
I am in the sudo group

adduser paul sudo
  The user `paul' is already a member of `sudo'.

addgroup sudo
  addgroup: The group `sudo' already exists.

But I get the  warning message:

paul is not in the sudoers file.  This incident will be reported.

It seems I have to restart the system.

 Web browser

Why Firefox has been rebranded as iceweasel.

"Debian was initially given permission to use the trademarks, and adopted the Firefox name. However, because the artwork in Firefox had a proprietary copyright license which was not compatible with the Debian Free Software Guidelines, the substituted logo had to remain."