THE FOLLOWING is a list of questionnaires from Martin Seligman's Positive Psychology Center. Seligman is the premiere researcher into happiness, depression, and personal strength, and his questionnaires are not hokey sideshow nonsense, but the real thing, used by researchers and therapists.
You can learn something about yourself that will really help you improve your mood in the long run. Follow the links and you'll find descriptions for each questionnaire, as well as links to download them.
You can use the "Subjective Happiness Scale" to measure your progress. Take the questionnaire and then try the methods on this site to raise your mood for say, a month, and then take the questionnaire again.
The most useful questionnaire in my opinion is "The VIA (Values In Action) Inventory of Strengths." It reveals your "signature strengths." A signature strength is not only something you're good at but something you also love to do. Add more actions that involve your signature strengths and you'll see your mood rise right off the chart!