I am currently having a great time writing the chapter "Crossing to Siberia." I'm also enjoying going through all my old notes, and sorting my research into chapters. I've started to write the book by hand, and found this actually much more efficient than using the computer. This is because I can spread my papers all over the place, take time out to be social and not get such a stiff neck from sitting in front of the computer screen.
A great friend of mine, Noon, encouraged me to write my chapters and outline on pen and paper, and I'm grateful for her suggestions and her constant encouragement.