PHP is a general-purpose server-side scripting language, originally a dynamic Web page technology designed for Web development. This is one of the first languages to embed server-side scripts in HTML documents, rather than calling an external file to process data.
Here are some very good PHP tutorials for you:
Build a Web site with PHP, MySQL, and JQuery Mobile
Use PHP and jQuery to display your favorite microblogging (Twitter)
Use testify.php to write some tests
Create a PHP +css3 page
Photobooth with PHP, JQuery and CSS3
Make an Ajax web Chat feature –php + MySQL
Features recommended applications for PHP, MySQL & JQuery
Use PHP to make pictures filtered
Create an API-centric application
Create a time-based CSS style switch
Create a donation page using the PHP, MySQL, and Paypal APIs
Design and develop an integrated Facebook application
How to create an advanced Twitter widget
Building a contact form using HTML5
PHP & MySQL File Download counter
AJAX-style instant sticker functionality to implement PHP & JQuery
AJAX-made Todo PHP, MySQL & JQuery
Make a cool login system
Create a polling page with PHP
How to implement a wireless scrolling album display