Some of the questions are:
1) Is it relevant for my assignment or research?
2) Is the author identified?
3) Is the author a person you recognise as an expert in his field?
4) Is the author affiliated to an academic institution or credible organisation?
5) Is the text well written and grammatically correct?
6) Are the sources cited reliable and can they be verified elsewhere?
7) Does the website promote a different viewpoint?
8) Is the information up to date?