This World Wide Web page written by
Dan Styer,
Oberlin College Physics Department;
http://www.oberlin.edu/physics/dstyer/RelativityQM/TheTerritoryAhead.html;
last updated 25 September 2014.
So you've read Relativity for the Questioning Mind and want to continue exploring and raising questions about "this strange and beautiful Universe, our home."
One way is through thoughtful, critical reading: There are a many different books about relativity at many different levels and from many different approaches. If you want to continue in the same direction as Relativity for the Questioning Mind into more professionally-oriented topics like the Lorentz transformation, energy, momentum, force, then I recommend these two documents that I wrote for my students:
If you want to continue into these professionally-oriented topics but using a different approach, which emphasizes space-time geometry rather than clocks and measuring rods, then I recommend:
If you want a popular-level glance at general relativity I recommend:
and if you want a popular-level biography of Albert Einstein try:
But you can do more than read, you can actually participate in research. Several "citizen science" projects are active, but I particularly recommend classifying galaxies through the galaxy zoo. As the organizers note, "You may even be the first person in history to see each of the galaxies you're asked to classify."