Digital Saskatchewan: php & mysql project

Greetings;
I have created a collection of over 7500 images and video clips. All images are free for non-profit use and the site itself is totally non-profit.
The site is called Digital Saskatchewan because it started with just Saskatchewan images. Now people are saying that they would like to create similar projects in other places, e.g. Digital Texas. I would like help in designing and creating an open source front end that would allow others to create their own site while sharing this database and image/video collection. Long term help as well as any suggestions would be helpful. Where do I get started with an open source project? How is it licensed? and a thousand other questions I havn't thought of yet!
Digital Saskatchewan http://www.saskschools.ca/~digital_sask/