The big draws in the sidebar are the Traffic Sources and Content links. Click Traffic Sources > Sources > All Traffic to see where your users are coming from. Under this header, the Search Engine Optimization > Queries link will give you a sense of the most popular search keywords that have the potential to lead to your site, and what portion of those clicks you're grabbing. The Content > Site Content > All Pages link is where you'll get an idea of what specific pages or products are generating the most traffic. Again, manipulate the timeline to ferret out long-term and short-term trends.
One of Google Analytics' selling points is its ability to connect to your AdWords campaign (so you can track whether your own ads are bringing in visitors). If you run ads on your site, click Content > AdSense > Overview to see which pages on your site are earning the most revenue (and how much). You'll need to link them together in the AdSense tool first.
Want reports sent to you by email? Click the Email button near the top of the page to have the specific report you're viewing sent to you regularly.
Next Page: Adobe Omniture SiteCatalyst and Alexa
Adobe Omniture SiteCatalyst
Omniture SiteCatalyst, once an independent product, became part of Adobe in 2009, and Adobe continues to update it regularly. SiteCatalyst is an exhaustive and in-depth tool, and it's widely considered to be the upscale version of Google Analytics, suitable for deep dives when Google fails to get the job done. Many companies use both tools.
Pricing is individualized based on each business and its traffic; Adobe refused to give us any details other than that. Anecdotal commentary on the Web suggests that you should expect to pay six figures for a basic version of the service, which puts it within reach for only very large Web-centric businesses.
SiteCatalyst provides more options than Google Analytics, and it can look complicated at first glance. The basics are easy to find, though. Just use the left sidebar to hit the highlights. Your traffic graph is available under Site Metrics, and your top pages are under Site Content > Pages Reports.
SiteCatalyst excels at reporting on the finer points of a campaign, including deep mobile stats, video plays on your site, and a breakdown of your search traffic, including whether it's paid or organic. You can easily get lost in all these reports, so be sure to take advantage of the email function (using the row of icons in the toolbar) to have them sent to you on a regular schedule.