Yahoo Finance – Here you can find information and news about stocks, and real-time stock quotes.
Market Watch – Here you can find more information about stocks and other investments, along with being able to manage your portfolio.
The Street – Here you can find business news, stock picks, and all other things neccasary to a healthy portfolio
CNN Money – Here is a more user-friendly looking site that one could look at many graphs/charts about stocks
Mutual Funds – Here you will find all the information you need to know about mutual funds