USB Host

Hello everyone, I want to conect a pendrive with the arduino. For this I want to use a USB host shield, the shield I want to use is attached to this question. What i need is: connect this pendrive to the arduino and copy data to file in this pendrive.
The problem is: I dont't know how to do that. I searched on the internet and I dont't understand where to begin. I need help for wich library I need to use it. and how to transfer some data to that pendrive. Thanks in advance!

usb mini shield.jpg

https://www.google.com/search?q=arduino+usb+host