Several celebrities experienced major career ups and downs in 2009, experiences that we could all learn from to help steer your career in the New Year. Here are a few:

1. You may remember what happened at the MTV Video Music Awards in September, when Kanye West, upset at Taylor Swift's best female video award, went onstage and voiced his opinion that Beyonce Knowles should have gotten the award. His behavior was deplorable, in people's opinion.

Lesson: Don't steal the spotlight from your co-worker. Give credit where credit is due and be gracious in praising others. We will all get our own 15 minutes of fame.

2. Kim Clijsters, former World No. 1 ranked tennis player from Belgium, announced her retirement in May 2007 but two years later came out of her retirement and picked up where she had left off, winning major titles at the Women's Tennis Association Tour.

Lesson: Choose your own path based on what's important to you. Kim was clear about her motives for retiring to start a family and then to come out of retirement. She made the time for family priorities.

3. Carrie Prejean was stripped of her Miss California USA title after a photo was revealed showing her partially nude. Before this, she stated that she opposed same-sex marriages, in response to a question put to her during the 2009 Miss USA pageant, and stating that she was a Christian.

Lesson: You're better off not stating your values in public if yours don't really hold up. Hypocrisy ruins reputations, and in the workplace it's best not to comment on other people's values as you never know whom you may offend.

4. David Letterman lost personal and professional trust after it was revealed that he had an affair with a staffer.

Lesson: It's best not to become romantically involved with workers who report to you. It would appear as a misuse of power, and that can be hard to overcome.

5. Oprah Winfrey announced that she would end her daytime talk show in 2011, stating that it felt right to her.

Lesson: When resigning, leave on a high note when the going is still good for you, and on your own terms when the timing feels right.