A good place to start is by skimming through the ever-growing list of frequently asked questions (with answers, of course). Then have a look at the rest of the online manual and other resources in the documentation section.
Books are convenient resources to begin exploring PHP. The titles listed here will help you to start learning PHP, as well as extending your existing knowledge.
There are a number of mailing lists devoted to talking about PHP and related projects. This list describes them all, has links to searchable archives for all of the lists, and explains how to subscribe to the lists.
The PHP language newsgroup is comp.lang.php. In addition to this many of our mailing lists are also reflected onto the news server at news://news.php.net/. The server also has a read only web interface at http://news.php.net/.
Mailing list messages are transfered to newsgroup posts and newsgroup posts are sent to the mailing lists. Please note that these newsgroups are only available on this server.
PHP user groups have started popping up. Christopher R. Moewes-Bystrom is running a PHP user group registry at http://www.phpusergroups.org/. There's also a list of user groups in Germany, as well as news from those same user groups, at http://www.phpug.de/.
A list of upcoming events (such as user group meetings and PHP training sessions) is included in the right-hand column of the front page.
If you want to list an upcoming event, just fill out the form on this page.
Looking for some more sample PHP scripts? Our links page page lists some archives of sample PHP code - great places to find many example scripts and useful functions, organized for your searching pleasure!
The knowledge base is a growing collection of PHP related information in a searchable question and answer format. Anyone can contribute, and everyone is encouraged to do so. You can visit the Knowledge Base at http://php.faqts.com/.
Otherwise known as IRC or Internet Relay Chat. Here you can usually find experienced PHP people sitting around doing nothing on the #php channel. on OpenProjects. There are also many PHP related channels on EFNet and on IRCNet (like #php and #php.de).
If you have a problem or suggestion with the PHP.net website, please contact the webmasters mailing list at webmaster@php.net. This mailing list is archived and also available as a newsgroup, much like all the other lists.