Importing PDFs and pictures

As an ESL teacher, I would like to be able to import PDF files in books and pictures. I could, this way, import tasks, cheat sheets and functionnal language so that students can work easily. I could set up posters with words they need to know, give them a book with the words they want to say to communicate with firends or even send a list of things to do in their world as an assignment. I know the boards can do part of that, but to reuse material I have would be useful.