Mark Cuban, yes the same Mark Cuban who owns the Dallas Mavericks, has a good post on business, opportunity, and winning the battles you are currently in.
“Its a huge lesson for entrepreneurs. Win the battles you are in first, then worry about expansion internationally or into new businesses. You do not have unlimited time and/or attention. You may work 24 hours a day, but those 24 hours spent winning your core business will pay off far more. It might cost you some longer term upside, but it will allow you to be the best business you can be. To use a sports metaphor, get the fundamentals right and then add to your fundamental skills before you try to take on the trick shots.”