The greatest levels of contentment and self-satisfaction are experienced by those who have found a way to serve others. In addition to the true inner joy that is created by serving others, it is a universal principle that you cannot serve others without it coming back multiplied to yourself.
Decide what is important to YOU
Take some time to determine what causes and groups of people are important to you. What issues call out to you? What organizations make your heart sing? Do you care more about the homeless or the arts?
If you love art and think that the schools are woefully lacking in art education, you might decide to volunteer to raise funds for art supplies, volunteer to teach an art class, or become a docent at your local art museum. If you were an only child and really missed having your father or mother around, you might want to volunteer for Big Brothers or Big Sisters. Perhaps you love animals and would rather help find homes for abandoned pets. If you love books, you could volunteer to read a book for the Recording for the Blind & Dyslexic.
* Source: The Success Principles by Jack Canfield