No one ever said that leading a business is easy--it's not. In fact, it can be frightening, exasperating, challenging, harrowing, and exhausting. When you feel like your leadership batteries are running low, turn to these words of wisdom for a quick boost.

1. "The key to successful leadership today is influence, not authority." --Ken Blanchard

2. "The most effective way to do it, is to do it." --Amelia Earhart

3. "No man will make a great leader who wants to do it all himself, or to get all the credit for doing it." --Andrew Carnegie

4. "Done is better than perfect." --Sheryl Sandberg

5. "What you do has far greater impact than what you say." --Steven Covey

6. "Keep your fears to yourself, but share your courage with others." --Robert Louis Stevenson

7. "The challenge of leadership is to be strong, but not rude; be kind, but not weak; be bold, but not bully; be thoughtful, but not lazy; be humble, but not timid; be proud, but not arrogant; have humor, but without folly." --Jim Rohn

8. "Forget about the fast lane. If you really want to fly, just harness your power to your passion." --Oprah Winfrey

9. "Efficiency is doing the thing right. Effectiveness is doing the right thing." --Peter Drucker

10. "There are two ways of spreading light: to be the candle or the mirror that reflects it." --Edith Wharton

11. "Tend to the people, and they will tend to the business." --John Maxwell

12. "The question isn't who's going to let me; it's who is going to stop me." --Ayn Rand

13. "Outstanding leaders go out of their way to boost the self-esteem of their personnel. If people believe in themselves, it's amazing what they can accomplish." --Sam Walton

14. "My job is not to be easy on people. My job is to take these great people we have and to push them and make them even better." --Steve Jobs

15. "As a leader, I am tough on myself and I raise the standard for everybody; however, I am very caring because I want people to excel at what they are doing so that they can aspire to be me in the future." --Indra Nooyi

16. "Leadership is the art of giving people a platform for spreading ideas that work." --Seth Godin

17. "The first responsibility of a leader is to define reality. The last is to say thank you. In between, the leader is a servant." --Max DePree

18. "To handle yourself, use your head; to handle others, use your heart." --Eleanor Roosevelt

19. "Leadership is the capacity to translate vision into reality." --Warren Bennis

20. "You manage things; you lead people." --Admiral Grace Murray Hopper

21. "The best way to predict the future is to invent it." --Alan Kay