I have been a long time subscriber to Dave Chaffey’s newsletter. They come out monthly and he always has a lucid perspective on some aspect of online marketing. One of the best resources that he has on offer is a presentation on SEO. Slide 3 gives a perfect overview of SEO in all its aspects summarized into one page.
The book is great in that it gives an exhaustive view into the specific tools, nature of customers, site design, media planning, budgeting of an online campaign. It includes case studies of how people have overcome specific challenges, as well as tips on how to get things done. it is updated as of last year, so you get updates on widgets, how to use Google Analytics- not just reviews on html e-mails.
If you have someone in your team that needs to get up-to-date on online quickly, this is a great resource. If you want to look at the basics in an easy to read manner, its great too- recommended.