Quality of OER is considered one of the barriers for adopting OER. As with critically evaluating other scholarly resources, you need to consider the 5W + 1H (who, what, when, where, why, how ) and relevance of an OER. In addition, you can:
Read more: OER Evaluation Checklist by Sarah Crissigner and [Summarized] Rubrics for Evaluating Open Education Resources Objects , summarized version of Achieve's OER Rubrics by Rodney Birch of George Fox University
OER resources listed below are not comprehensive but can be used as a starting point.
The open text resources and open access journal publications can be used as teaching materials but will require instructors' guidance and designing to be introduced into classrooms.