A few standard resources from the marketing world…
Search Engine Roundtable – Daily buzz and roundup of the search engine industry. If someone important says it, you can usually find Barry Schwartz writing about it here.
Search Engine Land – Led by Danny Sullivan, Search Engine Land is a must-read online publication.
Moz – Formerly known as SEOmoz, this is primarily an SEO software company, but perhaps just as well known as a marketing resource. Check out the Whiteboard Friday’s video presentations.
Local Search Forum – A discussion forum about all thing “local” in the SEO world. There are some good forum members here, and the owner; Linda Buquet is a top contributor to the SEO community and a well-seasoned local SEO expert.
Google Webmaster Central Forum – The official product forum for webmasters. If you are encountering issues (especially technical issues), this can be a good place to try and get things sorted out.
Google Webmaster Youtube Channel (and office hours) – Various videos from Google, plus video of the office hours Google+ hangout with John Mueller (Google Webmaster Trends Analyst). If you can’t find an answer to your question anywhere on the web and the Google forums are still not helping, consider stopping by John’s office hours to ask a question. Videos are uploaded to the youtube channel. Best for technical/indexing issues.