What I like most: Reading well-written sources that take me to another world for hours at a time - and being able to call that work! Also, of course, finding a gem of information that is either exactly what I was looking for, or else fits perfectly into the story in some way.
Each of my books has taken me a different length of time to write - eight months for 'Seesaw Girl,' eight months for 'Shard,' three years for 'When My Name Was Keoko!' The publisher takes another year and a half to work on the book, so altogether each book can take up to three or four years to publish.
With a book called 'Keeping Score,' I really did want to write a book about the Korean War, because I felt that it is the least understood war in the American cultural imagination. So I set out with the idea that Americans didn't know much about the Korean War and that I was going to try to fix a tiny bit of that.
My son and I discovered Terry Pratchett's books together, when he was about eleven years old. He'd be reading on his own and would start to laugh, and then eagerly read the passage aloud to me--and I'd do the same to him! Pratchett's books became a shared source of delight for us back then, and they still are today.