* The Millionaire Next Door.
* The Four Pillars of Investing
* A Random Walk Down Wall Street
I've seen fellow interns blow their salaries on 200 jeans, clubbing, and eating every meal out.
Meanwhile, the IRA I started in grad school is growing at ~7% a year providing a nice nest egg.
Financial security gives you the freedom to take risks. Some discipline in your 20s will make your 30s more awesome than you can imagine :)