Nice and simple instructions…
Lifted from http://www.devolio.com/blog/archives/221-How-to-install-Apache,-MySQL-and-PHP-LAMP-in-Ubuntu-7.10.html
Installing Apache
Now we can get started installing. This will take a few minutes, so grab a beer (or your favorite beverage,) and off we go. To install Apache, type or paste this into your terminal:
sudo apt-get install apache2
Testing Apache
Once apache2 is done installing, you can go ahead and test it by using:
sudo /etc/init.d/apache2 start
If you get a message that it’s already running, you’re good to go. Now, open up your browser and navigate to:
http://localhost
You should see a page just like this. As long as you do, we’re ready to install PHP.

Installing PHP
Again, to install PHP, type or paste this into your terminal:
sudo apt-get install php5 libapache2-mod-php5
Once it’s finished installing, restart apache, using:
sudo /etc/init.d/apache2 restart
Testing PHP
Now, let’s make sure that PHP is working properly. To do this, we’re going to run phpinfo(). You can, of course, swap out gedit with your editor of choice.
sudo gedit /var/www/phpinfo.php
Type or paste the following into the document, and save it. (remove the space before the ‘?php’)
< ?php phpinfo(); ?>
Now we can test PHP by browsing to:
http://localhost/phpinfo.php

You should see all of the info about your PHP installation listed on the page, like so. For security reasons, you should remove this page when you’re sure that PHP works.
Installing MySQL
Now we can conquer MySQL
sudo apt-get install mysql-server

As MySQL is installing, it will ask you to configure your root password. Make sure that you type it correctly, as it will only ask you once.
Testing MySQL
After that is finished, you can test MySQL by running this, where zzzz is your password
mysql -uroot -pzzzz
If it brings you to a MySQL prompt, you’re done! You can type exit to get out of MySQL.
Installing phpMyAdmin
Now, if you want to install phpMyAdmin to have a front end for MySQL, you can use the following
sudo apt-get install libapache2-mod-auth-mysql php5-mysql phpmyadmin

It will ask you to choose a webserver to configure automatically, you can use the space bar to select Apache2. And after that’s finished, restart one last time.
sudo /etc/init.d/apache2 restart
Finished!
Now you have your own LAMP (Linux Apache MySQL PHP) server, with phpMyAdmin.

Useful Commands and Default Locations
To Save yourself some time, you can make launchers for Apache or MySQL start, stop, and restart if you feel the need.
Apache
sudo /etc/init.d/apache2 start sudo /etc/init.d/apache2 stop sudo /etc/init.d/apache2 restart
MySQL
sudo /etc/init.d/mysql start sudo /etc/init.d/mysql stop sudo /etc/init.d/mysql restart
Locations
/var/www/ -- Document Root http://localhost/phpmyadmin -- phpMyAdmin /usr/share -- phpMyAdmin local location BUT Don't forget to fix phpmyadmin... sudo gedit /etc/apache2/apache2.conf
Scroll right to the bottom of the file that opens, and add:
# Enable PHPMyAdmin Include /etc/phpmyadmin/apache.conf
Now save, exit, and type:
sudo /etc/init.d/apache2 restart
(http://ubuntuguide.org/wiki/Ubuntu:Hardy#Simple_LAMP_server_Setup)