'The impetus behind Bandolier was to find information about evidence of effectiveness (or lack of it), and put the results forward as simple bullet points of those things that worked and those that did not: a bandolier with bullets. Information comes from systematic reviews, meta-analyses, randomised trials, and from high quality observational studies.'
CAUTION: this site appears to have no content more recent than 2009. But there is a huge wealth of valuable content up to that point including introductory material on many key aspects of evidence-based medicine as well as analyses around specific conditions and interventions. In the latter case, however, it must be understood that there will be more recent evidence available. But the methodological material will continue to be valuable.
The layout and navigation of the site leave something to be desired - there is more there than immediately meets the eye. For example there is an extensive look at alternative and complementary therapy (AT not included) which you won't necessarily find straight away: