Link Building

• http://www.searchenginejournal.com/natural-link-building/12582/

• http://www.seomoz.org/blog/link-building-for-small-ecommerce-sites

• http://searchengineland.com/a-case-study-using-contests-to-build-links-23776

• http://www.searchenginejournal.com/keyword-research-synonyms/12540/

Social Media

• http://econsultancy.com/blog/4408-five-easy-ways-to-make-your-business-website-more-social

• http://www.seomoz.org/blog/early-detection-how-social-media-may-save-the-world

• http://econsultancy.com/blog/4436-social-media-engagement-good-habits-are-hard-to-start

• http://www.searchenginejournal.com/how-to-target-users-within-social-networks/12558/

• http://econsultancy.com/blog/4451-what-can-email-marketing-learn-from-twitter-blogs-and-other-social-media-channels-2

• http://www.readwriteweb.com/archives/how_to_use_facebook_5_tips_for_better_social_networking.php

• http://www.searchenginejournal.com/why-employees-need-social-media-guidelines/12588/

PPC

• http://www.searchmarketinggurus.com/search_marketing_gurus/2009/08/dont-gamble-with-your-ppc-campaigns-save-it-for-the-casinos.html

• http://www.seomoz.org/ugc/increase-google-adwords-quality-scores-by-enhancing-user-experience

• http://www.thinkseer.com/blog/the-dos-donts-of-googlebase-avoid-the-headaches-keep-making-money/2009/08/21/

On Site

• http://www.seomoz.org/blog/perfecting-keyword-targeting-on-page-optimization

• http://econsultancy.com/blog/4413-e-commerce-delivery-options-key-tips

• http://www.seomoz.org/ugc/the-importance-of-nofollow-links

• http://www.searchenginepeople.com/blog/on-site-evaluation-in-action-what-where-and-how.html

• http://searchengineland.com/how-to-handle-an-seo-setback-24052

• http://searchenginewatch.com/3634740

Random

• http://www.getelastic.com/top-ten-2-dot-0/

• http://www.seobook.com/fox-news-blasts-seo

• http://www.seobook.com/google-adds-keyword-predictions

• http://wordpress.tv/2009/05/30/matt-cutts-google-sf09/

• http://www.seomoz.org/ugc/us-websites-break-into-uk-serps-join-the-invasion

• http://www.aimclearblog.com/2009/08/20/how-savvy-advertising-agencies-outsource-search/

• http://www.seomoz.org/article/search-ranking-factors

Tools

• http://www.searchenginejournal.com/firefox-addon-html-validation/12526/

update: edited to fix the broken links - sorry about that.