In a new tutorial on PHPBuilder.com today, they walk you through the use of the use of the mysqli interface in PHP.
This article will illustrate some basic techniques for using the mysqli interface. This is a great tool to use in php5 because it doesn't need any include libraries like PEAR, etc; it is compiled right into the distribution.
They start things simple, showing how to make the mysqli connection in your script, including how to set up the connection parameters. They move quickly into making queries on the database - first a simple one with a loop and then a more complex example with a prepared query. They wrap things up by helping you create a simple class that works as a bit of an abstraction layer to query and report on the results returned.