The IBM developerWorks site has already posted Part 2 in their "Learning PHP" series.

This tutorial is Part 2 of a three-part series that takes you from the most basic PHP script to working with databases and streaming from the file system by documenting the building of a document workflow system. Here, documents are uploaded by users and stored in a non-Web-accessible location for retrieval by the application in Part 3. We also look at working with XML files using DOM and SAX, and we look at exceptions.

Not missing a beat from the first part, they forge ahead, tackling a document workflow system to help you learn (I always find that having a project to learn with helps *so* much, on any language). Plus, they take a look at XML functionality in PHP, including both the SAX and DOM sides of things...