In order to run PHP programs you will either have to run it on a webhost that supports PHP (such as Hostmonster) or install a local server with PHP to run it on a local machine.
If you want to run PHP on your local machine, WAMP and XAMPP are Apache installations that bundles PHP, and MySQL database. They are good "all-in-one" packages to try. See tutorials on how to setup local PHP environment.
Some beginning tutorials that can get you started with learning PHP are ...
See more PHP tutorials sites here.
The official PHP site and reference is at php.net.
If you prefer to learn by watching videos, LearningNerd has 15 videos that are introductions to basic concepts in PHP. She was learning PHP as she was making the videos. However, I have watched all 15 videos and the materials presented are sound and she knows what she is talking about. They are good because she presents the major points in a very concise manner.
For more lengthy videos that will go into more depth, view the beginning PHP videos and then the object-oriented PHP videos on KillerPhp.com.
PhpVideoTutorials.com has a series of free lessons on PHP as well. It starts of by showing you how to install WAMP server mentioned above.
If you have never programmed in any other programming language before, start with learning the basic programming concepts such as variable, data types (such as string, integer, and float), and then the operators - both the arithmetic and string concatenation operators are important.
Next, you will need to learn the branching constructs and looping constructs. The both involves evaluation of conditions. So knowledge of comparison operators are essential.
As your program gets more complex, you will encounter the need for more complex data types such as the array and its methods. You will also have the need to define and call functions.
You will find tutorials on all these basic PHP topics listed in "Basic PHP Tutorials"
As your program gets larger, it is best practice to start using PHP objects and PHP includes. As part of code security, make sure you also filter inputs and escape outputs. Be aware of tactics used by hackers (such as form hijacking, SQL injection, cross-site scripting, and denial of service attacks) and how to prevent them. See tutorials on PHP code security here.
You may have the need to learn regular expression and to perform other PHP tasks such as picking random numbers, sending email, etc.
You will find tutorials on various advanced PHP topics listed in "Advanced PHP Tutorials".
