This document has been designed to provide an overview of open educational resources (OERs) for elementary and secondary education personnel involved in the selection, acquisition, and/or use of instructional materials--general and special education teachers, administrators, assistive technology (AT) specialists, technology and curriculum coordinators, and creators of curriculum resources. These and other stakeholders need information about how OERs can--and are--being leveraged in K-12 educational contexts to meet the needs of all students, including those students with disabilities. Situated at the intersection of where the OER field meets accessibility issues, this Guide details a variety of resources useful for evaluating and selecting appropriate and accessible OERs. Such resources can help decision-makers choose open educational resources that will be usable by the broadest range of learners present in their schools and classrooms. Lastly, the Guide outlines design challenges related to the creation of accessible OERs and points to useful approaches for creating OERs that are accessible for the widest possible range of users.