There are several databases (medical and non-medical in nature) for use in public health research. They include:
You can often find statistics through library guides, sometimes referred to as "LibGuides". Many of these guides include links to statistical websites freely available on the Web. Other times, you can find large directories online as well.
Some of the best guides include the following:
Michigan State University, MSU Libraries - Health Statistics Research Guide
PhPartners: Partners in Information Access for the Public Health Workforce
UC Davis, University Library - Health Statistics
You can also use a database like ICPSR, which will be covered in more depth in the next class session.