The flair with which you grow and prune your reading pile directly affects your career trajectory. Sure, you can learn from enlisting mentors and taking on new projects, but you can learn with the most focus and speed by reading on your own.

But don’t be swayed by the business book bestseller list. Instead, devise a reading plan for yourself that encourages major shifts in thinking; Leaps in your thinking encourage leaps in your career. Here are some guidelines for your summer reading:

Make summer a time for big questions.
All-day beach trips are great for long books. Blow up rafts promote uninterrupted thinking. Don’t waste these precious chunks of time on John Grisham.

Instead, think of a big question, the kind that has no right answer but lots of angles, and dive into the relevant reading. One summer, when I was looking for the meaning of my nine-to-five life, I asked the question: “What makes a career feel satisfying?" Another question that has ruled my summer reading is, “What sort of human-computer interaction is fun?"

Sometimes, the answer to the question isn’t nearly as revealing as just discovering what question really piques your interest.

Think like you’re studying for a mid-term.
For most of us, rigorous thinking ended in college. But the organized, complex, thinking that gets you through upper-level philosophy courses also makes you sharp at the office. So keep on your toes by reading about Supreme Court decisions: They twist and turn the Constitution in ways that will give anyone an intellectual workout; they’re not as dry as Kant and not as brain numbing as Martha Stewart’s lawsuit.

(Bonus: reality TV can’t hold a flame to some of those cases. For example, a guy kills a cop, and gets shot back – blind in one eye and paralyzed from the neck down. Another cop follows the guy to the hospital, and interrogates him. The injured man screams, “I’m about to die! Leave me alone!" Then he spews self-incriminating information. Legal gathering of evidence, yes or no?)

Read to understand people.
Your career is dependent as much on people skills as it is on how well you do your work. So I recommend An Na’s novel, “A Step from Heaven" (Front Street, 2001), which I love. It’s a kids book. (For those of you who don’t read kids books, you should. They’ll remind you of that terrible time of life that is junior high school, and then you’ll appreciate where you are in life now, no matter where you are.)

“A Step from Heaven" is about a Korean immigrants, and it does a great job of showing the barriers to success that people of American-born parents do not face. Think of these barriers when you manage someone who didn’t have all the advantages in life that you had. Remember that topics like patience and compassion are as important to your reading pile as leadership and finance.

Don’t read to stroke your ego.
Just because you have already accumulated a summer reading pile tall enough to last fifteen summers doesn’t mean that you have to read those books.

Our tendency is to be attracted to topics we already know a lot about. For a while, I was reading too many books about time management. I am a good time manager, so each book’s recommendations would allow me to say, “Great, I’m already doing that. I’m great." When I forced myself read about sales, because I was uncomfortable in that area, my reading became much more productive.

Force yourself to read in areas that are unfamiliar to you. Read about your weaknesses. Read about people who annoy you and topics that bore you. The best antidote to disdain is a deeper understanding.