To supplement your understanding of how Microsoft® Cluster Server works with applications before you begin programming, read In Search of Clusters by Gregory F. Pfister, ISBN: 0-13-437625-0. In Search of Clusters offers an excellent introduction to clustering technology including a description of the common programming models.
For an overview of Cluster Server concepts and components, read Cluster Server Concepts and Architecture. This topic discusses the clustering model employed by Cluster Server and the software components responsible for implementing the model.
If you will be creating a new resource type, read the Microsoft Cluster Server Administrator's Guide and become well-versed in using Cluster Administrator. The Administrator's Guide describes how administrators expect to interact with new types of resources, thereby helping you to create DLLs that conform to those expectations. Because most administrators will be using Cluster Administrator for this interaction, resource type developers typically write an extension to this application to handle their new resource types. Understanding Cluster Administrator's design is critical to producing a high quality extension.
If you plan to use the Cluster Automation Server, you should be familiar with Component Object Model (COM) and Automation. See the "COM and ActiveX Object Services" section of the Microsoft Platform SDK for information on these topics.
The reference sections of the Cluster Server SDK provide syntax and return codes, as well as directions on how and when to use particular functions, methods, structures, properties, and control codes.