Handy post from CircuitBasics.
n this tutorial, I will walk you through the process of installing an LCD touchscreen on the Raspberry Pi, step by step. Many LCD touchscreens for the Raspberry Pi include an image file that you can write to your SD card and get up and running pretty quickly. But what if you want to run a clean version of Raspbian, without all the bloatware included on the manufacturer’s image? Also, what if you want to install a different OS such as Rasbmc or XBMC? In these cases, you should follow this tutorial and go through the steps to configure it on your own. This works on the Raspberry Pi 2 Model B as well as older versions of the Raspberry Pi. Don’t worry, it’s not that hard!