My idea is to introduce CouchDB to a world where database-driven development generally refers to MySQL. By no means, this is meant to be disrespectful to MySQL, or SQL-databases in general. However, I'm a firm believer in using the right tool for the job.
He uses this first post to introduce some of the basic concepts behind CouchDB like document-oriented vs row/table-oriented, Couch's erlang roots and connecting to it via a RESTful or JSON interfaces. He gets into the basic installation (via a package) and how to connect to the server for a sample query. He also mentions some packages that can help abstract out the PHP layer from a direct connection like HTTP_Request2 or phpillow.