1. If the journal is open access, is it listed in the Directory of Open Access Journals (DOAJ)?
3. Is the journal indexed in a key database such as Web of Knowledge, PsycINFO, etc.
Additional questions to consider:
Sources: CARL website "How to asses a journal",
Consult these checklists for further help:
If you are unsure about the credibility of a conference, there are some things you can do: