Justin Silverton has posted a quick introductory tutorial on how to use the PostgreSQL database from inside PHP.

This is a simple guide on how to start connecting to a postgres database with php. I also assume that you already have a database setup with a table/tables.

He shows how to make a connection to a database, perform a simple query, and provides the names of some other "helpful functions" from the PostgreSQL part of the manual along with what they do.