apt-get update
You can use either Apache 1.3 or the newer Apache 2. If you are using Apache 1.3, make sure you have the following packages installed
apt-get install apache php4 libapache-mod-php4 php4-gd php4-imagick php4-mysql mysql-server
If you are using Apache 2, you need the following packages instead
apt-get install apache2-mpm-prefork libapache2-mod-php4 php4-gd php4-imagick php4-mysql mysql-server