Arduino Billboard

Hey! I have a client that is looking to make a rear projection billboard. The billboard is going to have several slides that it will cycle through. His idea was to just throw this on a DVD and have it cycle through. I figure this is a bad idea since it will require him to leave a DVD player out in the elements. Exposing it and leaving it to possibly being stolen. So my solution is to program an arduino that could cycle through these slides. However, since I'm new, I have no idea where to begin. I understand the basics of Arduino, but not much more than that. I'm looking for any guidance anyone may be able to give me. It would be much appreciated. Thank you!

What do you mean by slides?