On the PHPMaster.com site there's a new tutorial (from David Francis) about connecting to a database (a basic introduction using PDO) and doing some of the common operations with the connection.

Wouldn’t it have been better for them to able to maintain their database where ever they were? Of course, but how? Simple – put it online. [...] In this article I’ll focus on the essential elements of PHP you’ll need to use an existing Access database online. One other item that’s standard with a Windows installation is the availability of ODBC drivers. These are essential for the use of Access from PHP.

He includes a sample database structure (with "product", "product_category" and "category" tables) and includes some sample code showing how to connect to the remote database and perform some basic actions - select, update, insert and delete