Here is a list of essential and some important tools for running and Monetizing a website or your blog:
- Google Analytics – complete analytics on your website visitors.
- Google Adsense – Monetize the website. Display ads on website and earn money.
- Google Webmaster Tools – Set of tools to identify keywords for your site, top queries for your site and crawler statistics
- Feedburner (now, Google Feedburner) – burn RSS feed of your blog. Comes with many cool features like e-mail subscription, dynamic banner creation etc.
- Alexa – Provides traffic and website ranking. A good indicator of website popularity.
- Google Custom Search – Implement search on website without hogging your hosting resources. Comes with Ajax and developer API as well.
- Google Ad Manager – A tool to manage and sell ad inventory.
This much should get you getting for gooooood! Will keep adding in comments as I encounter more tools.