These are resources to assist you in marketing, both online and off, but primarily as it relates to the internet. They’re grouped into what I view as the stages one should take in planning a marketing campaign.
Google’s Keyword Tool
Google Webmaster Tools
WordPress.org (for install it yourself)
WordPress.com (which is simpler, but less powerful)
Netfirms (which also offers one-click WordPress.org installations)
Measurement and Analytics
Gmail (and how to use multiple addresses via Gmail)