If you are planning to deploy and customize the great System Center Operations Manager 2007, you should study the various management packs that are available for it.  Developing a management pack involves designing a health model for your application, meaning you have to define a taxonomy of entities and corresponding health states, relationships, discoveries, etc.  What better way to learn how best to do this than to study the existing packs? 

For this, you must figure out how to unseal a .mp file.  Lutz's Reflector can show you how in a hurry: an .mp file is an assembly with a single resource of type byte[].  The byte[] is a GZIP-compressed stream of Unicode characters that is the original XML document.  Spend a few minutes to do this - the resultant knowledge is worth it!

The second most important resource is AuthorMPs.com, which contains great information about the architecture of OpsMgr.  Enjoy!