Basic evaluation covers aspects of a source that could disqualify it completely as something you should cite in an academic assignment (and, ideally, any situation where your argument must be supported by reliable facts). Questions you should ask yourself include:
For a quick but thorough evaluation of a source, the SCARAB worksheet developed by McHenry County College librarians is very good:
For a more nuanced evaluation of your sources, you should assess the impact of the source. This can be done by evaluating the impact of the source itself, the author of the source, the journal or publisher advancing the source, and more.
This type of evaluation is particularly important in assignments where you must be thorough but selective about your sources. A good example is when writing a review article (or a literature review paper for class): you must have sources that support a thorough coverage of the topic at hand but can't include all sources on a topic. You must select the sources that are most relevant that have the most impact in the area of research.