List of suspect publishers (archived version Jan 2017)
Jan 2017: Beall's list of predatory publishers (https://scholarlyoa.com/) has been taken offline. A version remains in the Internet Archive which is what is linked to in this guide.
Beall's list of predatory open access publishers is well known in academic circles. While it serves as place to gather information about questionable publishing, one may disagree with some of the publishers on the list being "predatory." Additionally, the list only focuses on OA publishing, although subscription-based publishers are not immune from quality control issues.