Dear all,
in case you need some more help with the book:
You can find the pdf of the first chapters of the book here, under Reading: http://www.nand2tetris.org/course.php
And then, a couple of Swedish on-line bookstores, where you can order the book:
http://www.adlibris.com/se/bok/the-elements-of-computing-systems-9780262640688