Confession time. I remember very little of what went on in elementary school. I do remember, though, that twice a year we walked about ten minutes to the local branch of the Brooklyn Public Library.
Pesach vacation is a wonderful time to do things like read a book or visit a library.
This visit to the library of Rav Yisrael Meir Lau is an interesting insight into what makes up a personal library.
Of course, there are many on-line library collections that you might want to visit, like:
The library at JTS and their special exhibit of The Prato Haggadah;
The library at HUC and the collection of illuminated Haggadot that they have available;
The list goes on:
The British Library, Yale, The Library of Congress...
So visit a library. And take your students (and your kids).