Documentation of the Bukkit API can be found at jd.bukkit.org. You will see several links regarding the status of the build (Recommended, Beta, or Development) and the form of the documentation (JavaDocs or Doxygen). If you are new to reading documentation of Java code, you may prefer Doxygen. It includes useful features, such as a search bar and collapsible lists and diagrams. If you are already familiar with reading documentation then you may be more comfortable using the JavaDocs. In the following screenshot, both API docs are side by side for comparison. The traditional JavaDocs are on the left and the Doxygen documentation is on the right.
The following figure is the inheritance diagram for LivingEntity from the Doxygen site. Take note that on the site you are able to zoom in and click a box to go to that class.
I encourage you to browse through each documentation to decide which one you prefer. In this book we will be using Doxygen but keep in mind that both...