My office mate recommended me this free and easy to understand SEO book. It is easy to understand, so far anyway. I started reading it but due to my time commitment, I do not read as much as I would like. Also, I am still reading about time management, maybe in order to read more books in the future.
So, highly recommended by someone who really knows SEO!
And, for everyone interested in multilingual SEO and international Search, visit the Multilingual Search Forum!