Fake / predatory journals (typically open access journals that publish everything as long as they get paid for it) are a problem to scholars. A good starting point to identify them is Beall’s List with lists on publishers that publish a range of fake journals, single fake journals which are not related to the above publishers, as well as hijacked journals that look like the submission web page of the original version. Also searching the above web site is a good idea.

Update from 2018: The above web pages do not exist anymore in 2018 (but 2017 versions can be retrieved via http://archive.org. In addition, there is https://beallslist.weebly.com/ that even adds new entries. Another blog covering this topic is http://flakyj.blogspot.com/.

In addition to the above blacklists, there is also some whitelist by Directory of Open Access Journals (DOAJ). But beware: some journals appear even both on the blacklist and the whitelist...

Fake / predatory conferences are also a problem, for example those hosted by IARIA: I was once myself TPC member of the The First International Conference on Advances in System Testing and Validation Lifecycle (VALID 2009). As it was the first one and even published by IEEE, it was to me at that time not obvious that this is a bogus conference. Just when I as a reviewer never got access to the reviews of the other reviewers, it became obvious that no rigorous academic standards apply and I did not anymore accept to be TPC member of any IARIA conference (nor submit there of course).

Anyway, University of Iceland respects most publications listed in ISI - Web of Knowledge and Scopus which contain so far only serious publication targets.