Website Grader – Useful tool for measuring the marketing effectiveness of your website, get a free custom report in seconds with advice for your website
Marketing Sherpa – A great resource for case studies and insights into marketing tactics
Internet Marketing Blog – Articles about business strategy and Internet marketing
Web ink now – Online thought leadership and viral marketing strategies from award-winning author David Meerman Scott
HubSpot Internet Marketing – Internet marketing system that helps you get more website visitors, convert more visitors to leads, turn more leads into customers, and analyze every step of the process