The WebGUI works fine for configuring OpenVPN. If you want to create the keys on the pfSense host then there are stickies that you've already been directed to:
http://forum.pfsense.org/index.php/topic,4807.0.html
http://forum.pfsense.org/index.php/topic,2057.0.html
Otherwise, as GruensFroeschli said, if you don't say what you're trying to do it's impossible to help you - crystal balls are still on back order.