Links to sites on how to use the Internet and E-mail

SEO Book: Great posts on SEO and marketing. Clears up basic misconceptions many people have.
Bruce Clay: Community blog that reported fast and very well on the recent (2006) SEO conference. They have a nice personal touch with some great women bloggers.
Google blog: Official google news.
Google webmaster central: Official google news specifically for webmasters.
Matt Cutts: Unofficial google SEO blog. Matt Cutts is a googler that blogs about SEO and google a lot. A reasonably impartial voice from inside google. He also blogs on other stuff like gadgets and programming a lot. I subscribe to the SEO/Google feed specifically.
Search Engine Land: Great blog on SEO. If you are only going to read one, read this one.
Search Engine Round Table: Good blog on what's live at the various SEO related fora.
Yahoo search blog: Official yahoo! search engine blog. They are pretty good at keeping the webmaster community informed on changes in their search engine algorithms.
SEO-Chat Pagerank research: Check the pagerank of your competition in the google-serps.