Once you've found some resources to answer the excellent questions you developed in the first phase of research, you'll need to evaluate them for authority and appropriateness. Keep in mind that the context in which you are working can greatly impact whether a resource is appropriate for your use. As the Scripture says, to everything there is a season. Here in the library, we say, for every source, there is an appropriate use.
The first video below offers an overview of identifying different types of literature, whether popular, trade, or scholarly. If you prefer to read rather than watch, the links below offer a similar overview.
The second video gives a quick checklist for determining credibility.