Educators seek to develop 21st century skills in the classroom by incorporating educational materials other than textbooks into their lessons, such as digitally available activities, videos, and visualizations. A problem that educators face is that no review process similar to the formal adoption processes used for K-12 textbooks or the college-textbook review process exists for these types of online educational resources. However, educators need authoritative high-quality digital teaching materials. The scientific journal peer-review system offers a well-established model to adapt to the requirements of a peer review of educational materials. In this paper, we review ten review processes developed to evaluate digital geoscience educational resources and focus in detail on a rigorous iterative peer-review process recently developed by the Climate Literacy and Energy Awareness Network (CLEAN) project. This process builds upon existing efforts and emphasizes the "curation" of a digital collection that addresses the Essential Principles of Climate Literacy and the Energy Literacy Principles. Providing educators with thoroughly reviewed educational materials is especially important for fast changing, societally important, and sensitive areas such as climate and energy science.