"The aim of the DOAJ is to increase the visibility and ease of use of open access scientific and scholarly journals, thereby promoting their increased usage and impact. The DOAJ aims to be comprehensive and cover all open access scientific and scholarly journals that use a quality control system to guarantee the content. In short, the DOAJ aims to be the one-stop shop for users of open access journals."
Open-Access Journals are a great place to find scholarly research materials, because many OA journals abide by the same guidelines as traditional print journals. However, make sure you use the same level of evaluation on OA journals that you would use on a website on the free web as some may be predatory and not follow strict peer-review guidelines.
Check Scholarly Open Access, a blog run by a librarian, for a consistently updated list of journals that may display predatory business and research practices.