Publishing one's own work is essential in most academic areas. While some fields continue to put a lot of weight on books, writing journal articles is important in an increasing number of areas. The logistics of journal submission are not obvious. Nonetheless they are yet another aspect of academic professionalization that seems to go unaddressed in many graduate programs.
In this piece from Inside Higher Ed, Eszter Hargittai covers how you go about picking an appropriate journal for your paper and how you prepare it for submission. The assumption is that you have prepared a manuscript that you and your mentors feel is ready for consideration by a journal.