Lxml parse help

To implement a college project, I need to process XML files. For this I choose lxml after some research. However, I cannot find a good tutorial to help me get started. I cannot choose most specifically what type of parsing I should use. There is not much data in my XML files, but speed is the main issue, not memory.

Can anyone point me to some tutorial that can help me or some book I can find? I've already tried the tutorial on the lxml site but it didn't help me much. Is there a small application I can find to make out the XML parsing using lxml