Websites can be an excellent source of information, but it's important not to use too many (try to include as many books and journal articles as you do web resources in your reference list) as they are less reliable as sources than academic books and journals.
When you read web pages, you need to evaluate them carefully for their quality. Make sure they are good enough to be referred to in your work! Have a look at our Critical Thinking guide for help with this evaluation.
General health sites:
More resources for osteopathy:
There is more information on statistical sources on the Statistical Information Guide.