Boot using your installation media of choice. It will take up to several minutes for the Ubuntu installer to load and display on your screen, so be patient. During this time you should see a little man and a keyboard appear at the bottom of your screen briefly- press any key to continue. Once the installer appears on your screen, follow the step-by-step instructions UP TO STEP 4 (stop at Step 4, then read the important note about Step 4 below first) at the [http://www.ubuntu.com/download/help/install-desktop-long-term-support official Ubuntu installation guide]. Then proceed with the rest of the steps in the link provided.

In a terminal, go to ~/NVIDIA_CUDA-5.0_Samples. Then enter the make command, and let all the samples compile (this will take some time). If you get no compilation errors right away, that's good! It is entirely possible that not all the samples will successfully compile as each sample has its own set of dependencies. There is definitely one sample you'll want to run, though. From Using a Terminal, from the ~/NVIDIA_CUDA-5.0_Samples folder, go to /bin/linux/release subfolder, and run the deviceQuery sample (./deviceQuery). If it runs and you see information about your CUDA device, you've made it! :)