Open access resources are included in many discovery tools such as CatQuest or PubMed. You can also find them by going directly to an OA directory or publisher.
Publishing : An Open Access source is your best choice if you are looking for somewhere to publish OA, or need to research something without paywalls or affiliation requirements. Use Sherpa Romeo to review multiple open access publisher policies at once.
Reading : Other free resources include materials in the public domain and gray literature such as government reports and preprints. A publication may be in the Public Domain if it is old enough to no longer be subject to copyright, or if it was produced by a government body and never under copyright. Open Access and Public Domain resources are all available to read.