text: My tools, in order of complexity:\n\nBenjamin Graham's book "The Intelligent Investor"\n- This will tell you what to look for\n\nYour network of friends\n- The companies you do business with are the easiest for you to know.  Do they have good products?  Are employees happy?  The devil's in the details.\n\nYahoo! Finance\n- A vast amount of free, reasonably up-to-date information\n\nCompany websites & annual report\n- Watch out for the marketing pitch!  If you know what to look for, you can find it here.\n\nSmartmoney.com Stock Screener\n- Good for separating wheat from chaff.  Make the list of stocks you want to concentrate on smaller.\n\nwww.backtest.org\n- For those with a more quantitative bent (ie: you want a computer to tell you what to buy) then this is a good place to start to learn the craft.\n\nBloomberg (pricy)\n- The industry standard for investor information, but it'll set you back the equivalent of a mortgage (~$1400.00/month)\n\nMarketQA (definitely not for beginners)\n- Another expensive tool, but good for advanced quantitative analysis.\n\nMatLab\n- Incredibly powerful tool for quantitative analysis.  Short of writing your own software, this is as good as it gets.