Critical Appraisal Worksheets - from the Centre for Evidence-Based Medicine, interactive forms for evaluating articles on diagnosis, harm, therapy, eprognosis and systematic reviews.
CONSORT - a checklist designed for authors to clearly report information from randomized controlled trials, but also useful in evaluating such studies.
RATS - Qualitative research review guidelines.
STARD - Standards for reporting on diagnostic accuracy. Checklist for studies - click on STARD checklist on the left.