I recently read a great book by Martin Seligman “Authentic Happiness: Using the New Positive Psychology to Realize Your Potential for Lasting Fulfillment”. Seligman makes a compelling argument that psychology can do more than relieve suffering but in addition can help people achieve happiness. He lists various things that do not provide much genuine happiness (eg. money) and that optimism is essential to finding happiness in life. Pessimists are less happy and live shorter lives than optimists. Healthy relationships and meaningful life goals are important. His TED talk provides a good summary of his ideas:
https://www.ted.com/talks/martin_seligman_on_the_state_of_psychology
He suggests that we will find happiness when we identify and use our strengths on an ongoing basis. He has a survey in his book and on his website to help people identify their key or signature strengths. http://www.authentichappiness.com.
What is the difference between a job and a career? The later is more likely to be satisfying. It is possible that a person can find happiness in many careers, ideally one that uses your signature strengths. An interesting idea is “job crafting” which is to change your job in ways that make your job more meaningful. A video on this subject is https://www.youtube.com/watch?v=C_igfnctYjA which is a talk by Amy Wrzesnewski on job crafting.
Another idea that has generated a good deal of interest in the field of positive psychology is “flow” which are activities that we find so absorbing that we lose track of time. A TED talk on this idea is “Flow: The Secret to Happiness:
http://www.ted.com/talks/mihaly_csikszentmihalyi_on_flow
He defines flow as “the state of gratification that we enter when we feel completely engaged in what we are doing”. Almost any activity can bring about this state of mind if it something you love or have talent for. Common examples are art, music, and sports.