If you are new to Ubuntu, and want to install PHP, MySQL and Apache, simply goto the Terminal (gnome-terminal) through:
Applications -> Accessories -> Terminal
and write the following commands:
1. Apache HTTP Server:
sudo apt-get install apache2
To start the Apache server, you have to write:
sudo /etc/init.d/apache2 start
To stop the Apache server, write:
sudo /etc/init.d/apache2 stop
To restart, write:
sudo /etc/init.d/apache2 restart
2. PHP 5:
sudo apt-get install php5 libapache2-mod-php5
3. MySQL Server:
sudo apt-get install mysql-server
After these installations, restart the Apache server by typing:
sudo /etc/init.d/apache2 restart
After successful installation of the above mentioned steps, simply write http://localhost/ on your browser, and see if you see the text: It works
Now goto the folder where you have to place your other PHP projects or files i.e. /var/www and change the index.html file to index.php, and by editing it, write some PHP code in it to check if PHP also works in it e.g.
<?php echo ' It works on PHP too ' ; ?>
Simple isnt it? Now start working on your different projects with PHP and MySQL on Ubuntu.