I would also recommend Feedburner.
There are many metrics to monitor for growth of a blog. Looking at traffic numbers is only one point. Time on site (I.E. visit duration) is critical.
In order to provide a worthwhile metric, you must first identify the goals you have, the audience you want to reach, and your niche targets for penetration. If you have already saturated an audience, growth becomes a matter of increasing frequency and duration.
Here are some tools you can use:
Compete.com is a good place to analyze yourself against several like-minded sites.
Quantcast allows you to see additional information you (or competitors) have for demographics, as well as where visitors are wandering.
Exactfactor.com allows you to track your search engine keywords for free.
Quarkbase.com allows you to see traffic patterns across Alexa, Compete, Blog Reactions, and several social media sites (Digg / Stumble / etc)

