Please recommend a good SEO - SEM book

[Jorge]

What would you guys recommend as the top books in SEO - SEM.
The most up to date.
The easiest to understand for beginners.
More valuable in terms of tips or difficult to find info etc ...

This field is tough on paper books, the minute one is out it is dated. You also have a lot of conflicting information depending on the source. Or books that are too vague or too specific. I'd love to find a book that is specific for SEO and SEM but blends in traditional marketing concepts that should never be forgotten.

[JasonD]

Aaron Wall's SEOBook.com