This is a very simple step-by-step..
1.Install geoip via yum: yum install geoip geoip-devel
2.You also might want to download database with ip addresses from Maxmind website and place it in /usr/share/GeoIP (which is a default location of geoip upon installation).
3.Install PECL extension: pecl install geoip
4.Add extension=geoip.so to your /etc/php.ini
5.Restart: apachectl restart
