When asked what advice he would give a young investor trying to enter the business today, Warren Buffett (remember, this is the man that had you invested $10,000 in his partnership in 1956 you would now have around $259 million) said that he would systematically get to know as many businesses as he could because that bank of knowledge would serve as a tremendous asset and competitive advantage. When you wanted to buy copper companies, for example, you would already have an idea of which companies operating in that industry and the various financial characteristics of each. (When the host of the television show responded to Buffett, But there are 24,000 publicly traded companies! Warren responded, Start with the As).
Some great resources are the S&P Stock Guide, the Value Line Investment Survey, and various trade journals and reports such as the Polk Bank Directory and the A.M. Best books.

