I dont know so much about business as I do price evaluation. A great book that really enlightened me on investing abroad is called:
The Either/Or Investor by Clark Winter ... great read. I bought it on ebay for like $8, lol. Cramer always has good insight on where he thinks the market is going, and he's usually right (or at least close).
I dont recommend listening to big whigs though, they're all smoke and mirrors. They'll tell you not to do something, but then they'll turn around and do it. Most investors/traders say to stick with the best of breed. While this may be true in some cases (like Microsoft when it had no Operating System competitors), I highly disagree with this theory (as does Clark Winter). You make your money by investing in the smaller companies that are going to be taking away revenue and profits from the big boys and swaying customers to come to them. It also spurs creativity and new products always catch people's eye.
Any way, major things to look for when evalutating stocks are the P/E, PEG, Price to Book Value, Price to Sales, and one I like to throw in is Price to Cash (sounds stupid, but who wants to invest in a company with no $$ to do anything new or innovative?). Hope this helps you get started. Also, investopedia.com is a great resource for definitions of the above terms (except for price to cash, that's my own). GL