Johns Hopkins Evidence-Based Practice for Nurses and Healthcare Professionals, Fourth Edition by 
How to Read a Paper by This video, from Joel Gagnier, Associate Professor in the Department of Orthopedic Surgery and Epidemiology at the University of Michigan, introduces four steps for the evidence-based medicine process.
When searching for evidence in the literature, pay close attention to research methodologies and how studies were done.
The following articles focus on the autism / vaccine debate. The Wakefield article is the original article that ignited the debate; the rebuttal, published the same year, is based on epidemiological methodology.
The Wakefield article was retracted in February 2010, but the debate continues.