The Library of Congress' new Thomas Jefferson library exhibit is now available online (in an abbreviated but interactive form). It provides a good brief overview of the reconstitution project and offers a selection of digitized books from the collection which are available for browsing. I hope there would be a few more of these, but I really like that they've highlighted Jefferson's use of the Baconian classification system for his library.
Until I can get to DC and see the "real thing," the online version will suffice - I'm delighted that they've done it, and I think it's a very adequate introduction to the library and its contents.
[NB: Once classes (finally) end next week and I've finished up some final work on the Mather Library I'm going back to Jefferson's LT library to make some further enhancements there. So be on the lookout for those.]