As a lay historian who has only taken one class in history at the college level, I find that not only am I not really aware of the latest developments or seminal works in the fields I'm interested in (Mostly Ancient Mediterranean Military history and Byzantine history), I don't really know where to look. I'm aware of databases like JSTOR, but I don't really have the background knowledge necessary to search for and evaluate sources with any kind of ease. In general, how do you recommend those of us without formal education in the field keep abrest of the important works in the field, and specifically, what are some books/journals that everyone in my field of interest should be reading or following. (Mostly talking about secondary sources here, but if there's a primary source you think might be obscure enough that I haven't heard of it, feel free to recommend away) The second half of the question is more relevant for the Byzantine history part of my interests, as the reading list provided is a bit spare.
Look on the web for syllabi for graduate reading seminars in your fields of interest. Also, find history departments that publish comp exam reading lists for their graduate students. These are typically broader than the seminar lists - like "19th century US history" versus "history of US slavery." These lists are very good for identifying what historians consider the most important works, although they are rarely the most recent works.
For Byzantine, check out the book "Byzantine Matters." It's a great overview of the state of the Byzantine field and is a great intro if you're looking to get into actual Byzantine work.