I am not very good at book challenges, I still haven't finished the Orbis Terrarum challenge that I started back in April, but even I can manage this one. Juliet on the Muddy Island asks us to sort our books so that their titles can be read in sequence. You can read all about the official Sorted Books Project and enter the Musings' version here.
I found these books almost already arranged on a shelf. I can see that I'll be looking critically and imaginatively at all my shelves now, I could possibly even do some dusting!