How can I evaluate the quality of online healthcare material?

Superb question. Becone an experienced, knowledgable, wise, well-read and educated physician... Well, i suppose that answer is not very helpful. The most important assessment of the material is an assessment of the source. Reliable sources generally come out of well respected institutions, that have oversight committees that evaluate all before publishing, usually preceding on-line; 2 examples: jhh journal, nejm.