Steps to build a Wordpress server

apt-get update
apt-get install apache2 libapache2-mod-php5 php5-gd php5-mysqlnd mysql-server

Enter MySQL root password twice

Run the MySQL secure installation script:

mysql_secure_installation

NOTE: Apache is configured to run as www-data in /etc/apache2/envvars:

export APACHE_RUN_USER=www-data
export APACHE_RUN_GROUP=www-data
mysql -p
create database wordpress character set utf8;
create user 'wordpress'@'localhost' identified by 'secret';
grant all privileges on wordpress.* to 'wordpress'@'localhost';
quit;
cd /var/www
wget http://wordpress.org/latest.tar.gz
tar xf latest.tar.gz
chown -R www-data:www-data wordpress
cd wordpress

If you want Wordpress to be your default site for the configured interface simply modify /etc/apache2/sites-enabled/000-default:

cp -p /etc/apache2/sites-available/default /etc/apache2/sites-available/default.orig
vi /etc/apache2/sites-enabled/000-default

If you already have a default site simply create a new vhost config file under /etc/apache2/sites-available/wordpress and run:

cp -p /etc/apache2/sites-available/default /etc/apache2/sites-available/wordpress
a2ensite wordpress
vi /etc/apache2/sites-enabled/wordpress

Enable Apache rewrite rules:

a2enmod rewrite
/etc/init.d/apache2 restart