Photo Based brochure type web application

I am in need of help figuring out how to approach a project that has been given to me.

I have very little working knowledge of the parts needed to make the project work.
If anyone can provide a starting point, component suggestions or even a full solution it would be highly appreciated.

I need to come up with a customizing brochure system.

Basically a user sits in front of their computer 1000 miles away and is presented with a brochure template. They are also shown a set amount of photos that they can drag and drop into predetermined sections on the brochure. Once they have made the selections on what photos to include on the brochure, they click download.
Up pops a High Quality PDF for them to print.

I know there are many parts to this project, showing a brochure with predetermined sections, allowing drag and drop of images into those section and then the background processing of creating a high quality PDF.

I think this is all how a comon photobook online works.

To recap, tt needs to be able to:
1. Show a certain amount of images to a user.
2. Show a brochure template with predetermined "placeholders" for images.
3. Allow a user to drag and drop up to three of the images onto the template (and show them the result)
4. Create a high quality PDF for the user to print.