PHP is the most important server side language to understand these days since it is the most widely used development framework for websites.

Once you have mastered the basics of HTML and CSS, it is time to learn PHP.

Although it is easy to learn in my opinion, a problem is that it has a vast amount of functions, so you may be overwhelmed with where to start.

So to learn PHP fast, I recommend following tutorials on how to implement practical things in web pages. For example, web page customization depending on the visitor. Sending yourself an email. Altering javascript with PHP.

This way you will learn what is important to know right away and not spend a lot of time studying things that you may not need for a long time to come.

To make your learning experience more comfortable, I highly recommend testing your code on your computer rather than continually uploading to the web and refreshing your browser. This will save you a lot of time and frustration.

And when entering the code, use a code editor that highlights the PHP with color so it is easier to spot typos and read the code.

The following tips contain links to Windows resources (Linux users may already have a suitable web server environment installed on their computer).

To run PHP on your computer, install an Apache web server {Win32 Binary without crypto (no mod_ssl) (MSI Installer)}, PHP5 (Windows Binaries -> PHP5 Installer) and MySQL (MySQL Community Server). You can download these from the respective websites or install a pre-configured package such as XAMPP.

And for editing your code use NotePad++

For serious development work and having the ability to step through your code for easier debugging, I recommend Net Beans IDE.

And to learn PHP fast check out Learn PHP in 17 Hours.