You can study the Book of James by reading it carefully and using a commentary as a guide to help you understand what you are reading. Commentaries provide general overviews, in-depth explanation of verses and information on the background of the book.
The Book of James is one of the epistles (letters) found in the New Testament of the Bible. Unlike the letters of Paul, James is not addressed to a particular congregation and is classified as a "general" epistle. With only 5 chapters, the Book of James can be read fairly quickly in one sitting.
Reading a commentary along with the letter is one helpful way to study it. Commentaries are written by scholars with advanced education in biblical languages and literature. These works come in a wide variety of lengths, intended audiences and theological perspectives.
Selecting a commentary can be a daunting task because of the sheer number of options available. You can help narrow your selection by answering a few questions: Do you want a general overview or a detailed study of chapters and verses? Are you coming to the text as a Christian believer or as a person with non-religious interest? Knowing your own perspective and your goals for studying can help you narrow your selection of study resources.
Biblegateway.com offers free access to a variety of commentaries, including commentaries on the Book of James. While the commentaries come from different time periods and theological perspectives, they all come from an evangelical Christian perspective. The "Ignatius Study Bible" series from Ignatius press offers a helpful commentary on James from a Catholic perspective. If you are studying James as a work of literature, "The Literary Guide to the Bible" by Robert Alter, while technically not a commentary, is a helpful companion.