Installing a driver on Linux used to be quite difficult, but in the past few years the process has become quite common. Here is a short tutorial on how to install the latest certified drivers from Nvidia, 310.19.
After the launch of Steam for Linux, Nvidia has released two major driver versions, featuring a huge number of improvements. Unfortunately, it can take quite a while until these drivers are available for all users, through the official repositories.
We installed the drivers in Ubuntu 12.10 (Quantal Quetzal), the 32-bit edition and everything worked smoothly. This procedure will work for most Debian-based distribution.
If you have another operating system, you can try the manual installation, but the commands might vary from one distribution to another.
The simplest way is to install a PPA which provides the latest Nvidia proprietary drivers. Just open a terminal and enter the following commands (you will need root access):
sudo add-apt-repository ppa:xorg-edgers/ppa
sudo apt-get update
sudo apt-get install nvidia-current nvidia-settings
Be careful not to use the 'dist-upgrade' command. The PPA contains other packages and you will end up updating stuff that you didn't want.
After installing the driver, open Unity and search for a package called Software Source. In the second tab called 'Other Software' locate the PPA and delete it.
The other way of installing the driver is to do it manually. Download the appropriate version of the driver, 32-bit or 64-bit and run the following command, in the folder containing the file (we'll exemplify with the 32-bit version):
chmod a+x NVIDIA-Linux-x86-310.19.run
You will then have to enter CLI mode by pressing CTRL+ALT+F2. Navigate to the folder where the driver was downloaded.
sudo service lightdm stop
sudo sh NVIDIA-Linux-x86-310.19.run
After the computer reboots, the new driver will be installed. The problem with the second type of installation is that whenever you make a Linux kernel update, you'll also have to reinstall the video drivers.
Check out this comprehensive Softpedia article to find out what Nvidia drivers you need and where to find them.