Apache is an option. Assuming you don't exactly know how to get the job done, I would go for a full package, including PHP, MySQL and Apache. My guess is that
WAMP would be a great choice. After you have installed the package you can start using all three of the applications, it even has a phpmyadmin installed in it.
All you have to do after installing is routing it outside your own network. Meaning, you have to install a virtual server on your modem/router to route your internal ip-address outside your network.