Google the journal to find their website. You may also Google to find more about their reputation, etc.
Identifying Predatory Journals
Whether or not a journal is predatory can be a difficult question to answer. While some journals are flagrantly predatory, there are journals that operate on a spectrum between flagrantly predatory and strictly legitimate. One warning sign to look out for are "cattle call" emails inviting authors to submit articles. It is often a good idea to ask colleagues for their opinions on the legitimacy of an unfamiliar journal before submitting an article to it. There are actual cases of scholars asking for their article to be withdrawn after realizing they have unintentionally submitted to a predatory journal only to have the journal publisher demand a fee for the withdrawal of the article, thus preventing the author from submitting to a different journal.
The following resources provide provides useful tips for identifying predatory journals:
The Directory of Open Access Journals (DOAJ) is a searchable database that helps scholars identify free, full text, quality controlled scientific and scholarly journals in their disciplines. It is a good starting place, but make sure to double check.
Predatory journals exploit features of Open Access and traditional publishing in order to make money from researchers. They often:
accept articles quickly
lack a true peer-review process
claim to be indexed in places where they aren't
They take advantage of both the large number of journals available and also researchers' need to publish quickly in order to progress in their careers.
Bottom line: you should avoid publishing in predatory journals.