There are simple qualitative measures that you can use to evaluate the impact of a journal in your discipline.
Journal Acceptance Rate: If a journal publishes the number of submissions and accepted publications on its website, divide the number of submissions by the number of accepted pieces to get the journal's acceptance rate. A journal with a low acceptance rate is more discriminating -- and presumably more prestigious -- than one with a high acceptance rate.
Editor's Reputation: Researching the editor of a journal can help you gauge the journal's quality. An editor who has published and been well-reviewed, presented at major conferences in your industry or otherwise contributed to the literature in your discipline is more likely to lead a reputable journal than an editor who has not contributed to the literature in your discipline.
It's natural to want to have your work published in the best possible outlet. There are many tools to use when evaluating well-respected journals in your field.
As defined by Budapest Open Access Initiative, "by 'open access' to this literature, we mean its free availability on the public internet, permitting any users to read, download, copy, distribute, print, search, or link to the full texts of these articles, crawl them for indexing, pass them as data to software, or use them for any other lawful purpose, without financial, legal, or technical barriers other than those inseparable from gaining access to the internet itself. The only constraint on reproduction and distribution, and the only role for copyright in this domain, should be to give authors control over the integrity of their work and the right to be properly acknowledged and cited."
Created by Scholarly Publishing and Academic Resources Coalition (SPARC), here is a three minute video on Open Access 101. Learn more at the Open Access LibGuide.