Q: What books will tell me more about Warren Buffett?

A: One of the best is Roger Lowenstein's "Buffett: The Making of an American Capitalist" (Random House, $19).

It not only covers his fascinating life (so far), but also offers an introduction to his way of thinking and approach to investing.

Alice Schroeder's "The Snowball" (Bantam, $20) is a very detailed biography.

Learn about other great investors, too, such as in John Train's "Money Masters of Our Time" (HarperBusiness, $16).

Smartest investment

Profitable stupidity

Dear Fool: In 1959 a friend suggested that IBM was a solid investment. I knew nothing about stocks, but I bought four shares at $441 apiece, for $1,764.

I panicked when the stock fell by $128 soon after, but that was followed by an avalanche of enriching progress.

My wife and I ended up selling the shares for a bit more than $7,000 to pay off our house. Rarely is stupidity profitable, but fortunately, for us it was.

The Fool responds: You weren't stupid — you were, like many, if not most, Americans, just not very informed about and experienced with the stock market.

You're right, though, that by diving in without having done much research, you were taking a big chance.

Some might suggest that you left a lot of money on the table by selling the stock that would keep growing for a long time, but by moving the money into your home, it boosted your worth, too.

IBM stock has grown by an annual average of 10.7 percent over the past 30 years, enough to turn $1,000 into more than $21,000.

The Motley Fool take

A Big Southern grower

In case you haven't noticed, DirecTV (NYSE: DTV) is doing a great job, posting 11 consecutive quarters of double-digit revenue growth.

It has been adding subscribers at a record rate — mainly because of Latin America, which offers a market of 140 million households eligible for pay TV. Rival Dish Network is not focused on this emerging market, so it's essentially DirecTV's for the taking.

And the company is taking it: In the first quarter of this year, it added more than 600,000 net subscribers in one quarter, double year-ago levels. Countries such as Argentina, Venezuela and Colombia are driving growth, all places where pay TV penetration is still in its infancy and offers immense opportunity.

DirecTV's approach to the Latin American middle class is smart, offering value-priced services that bring customers in the door and allow for up-selling down the line. The U.S. market is more mature, but even there, revenue recently rose 7 percent. The main problem facing DirecTV today is the cost of installing and upgrading systems for consumers. Stronger currencies down south are also putting pressure on profits.

Still, with a forward price-to-earnings (P/E) ratio recently near 9, this high-growth company is trading at an attractive price.

It's not dirt cheap, but its margin of safety makes it rather undervalued for long-term investors.