Website Grader - Useful tool for measuring the marketing effectiveness of your website
Marketing Sherpa - A great resource for case studies and insights into marketing tactics
Business Marketing Association - News and articles form one of the larger associations in the industry
Internet Marketing Blog - Articles about Internet marketing and small business strategy
On Startups - Articles about strategy, raising financing, and hiring for startups and small business
Web Ink Now - Articles about online media and viral marketing
How To Generate Leads Blog - Blog about Generating Leads from Online Marketing and Online Business Networking written by HubSpot's Peter Caputa IV.