Free keyword optimization tools, and SEO tips

http://www.google.com/trends
http://www.google.com/insights/search/#
http://adwords.google.com/o/Targeting/Explorer?__c=1000000000&__u=1000000000&__o=te&ideaRequestType=KEYWORD_IDEAS
http://www.keyworddiscovery.com/search.html#

http://seojr.com/8-most-important-seo-tips/