Doing research on a public-traded company is a great way to learn about different factors that drive decision-making among investors and industry competitors.  Public-traded companies are required by law to make a lot of information about them public, so research on them is a lot easier than trying to get comparable data about private companies.  Nevertheless, as with most thorough research projects, you will typically need to consult several sources to get all the information you're after.

Photo Credit: Ryan Lawler, http://en.wikipedia.org/wiki/File:NYSE127.jpg , Public Domain