I’ve been looking for an easy guide on setting up OpenVPN on the Raspberry Pi. I stumbled across this video on YouTube which was useful- http://www.youtube.com/watch?v=O7D7UkA3IKQ
I did have to make a few changes though e.g. replacing the local Raspberry Pi address with the address of my dynamic DNS provider. I also had an issue with the default port and protocol (UDP 1194) and had to replace it with TCP 443.