A good source of public company information. Enter the ticker symbol and go to the quote screen. From there you'll find links to a company profile, financial statistics, a stock chart and a collection of news about the company from Reuters, Business Wire, PR Newswire and other reputable sources. Also good for historical stock quotes, and real time quotes.
For company value, go to the statistics page for your target company and find the Market Cap (total number of shares X current stock price). Also look at the Enterprise Value (Market Cap + debt - cash) for a more complete estimate of company value.