I am teaching positive psychology for the first time this semester. One way to quickly teach students that this isn't just Happy Psych. 101 is to show them convincing data collected by an international organization (here, the United Nations) that demonstrates the link between positive psychology and the well-being of nations.
This data isn't just for a positive psychology class: You could also use it more broadly to demonstrate how research methods have to be adjusted when data is collected internationally (see item 4) and as examples of different kinds of data analysis (as described under item 1).
1) Report on international happiness data from the United Nations.
If you look through the data collected, there is a survival analysis related to longevity and affect on page 66. A graphic on page 21 describes factors that account for global variance in happiness levels across countries. There is also a lot of data about mental health care spending in different nations.
2) A quick summary of a few data points from National Geographic.
Including points that have been made previously in positive psychology circles: a) living someplace with nice weather doesn't lead to happiness, b) after basic financial stability has been achieved, happiness doesn't increase in proportion to one's income.
3) Data, visualized, via Huffington Post.
4) Another rich source of well-being data comes from the Gallup polling organization. They collect data on various aspects of wellness, including subjective well being as well as health data from the US and around the world. Included are weekly polls on if Americans feel that they are thriving, struggling, or suffering as well information on how well-being data is collected internationally.
5) Finally, The Onion's take on America's ranking as the 17th happiest country in the world.