Medscape is a useful resource for keeping up to date with a range of developments across the medical and health related fields

while the list is not provided as an evidence based indicator of relative credibility, Beall's site and blog do give quite a bit of 'food for thought'. There are certainly a number of dodgy publications, and like many I have been bombarded by invitations to publish, act as a guest editor etc. If you dont work for an organisation willing to pay the cost for open access publishing, it is an expensive option for individuals. There needs to be a clearer means of determining relevance and credibility of material at times.