Matt Cutts – The famed Google engineer’s own blog.
Search Engine News – A great way to keep up with the latest trends in the industry.
Search Engine Watch – a great sources of constantly updated articles
Site Pro News – An excellent free source of SEO articles.
SEO Chat – a large resource of SEO tools, news, and forums.
Google Webmaster Central – Official news on crawling and indexing sites for the Google Index.
SEO Chat Sources
SEO Chat Forums – Includes threads on specific search engines, PPC, link directories, and more.
Search Engine Forums – Includes threads on SEO, marketing/traffic building, hosting/maintaining sites, and more.
Digital Point Forums – Includes threads on specific search engines, marketing, business, design, and more.