Does that medication really work?

How do we know whether a particular drug, therapy or operation really works, and how well? How reliable is the evidence? Are clinical trials truly unbiased?

Recommended for their plain-language approach to answering these questions are  Testing Treatments: Better research for better healthcare by three doctors and a health advocate, and the University of Sydney’s Smart Choices: Making sense of health advice.

And even better, both are free downloads.