I'm not aware of one grand, overarching sample application that shows everything about Enterprise Library.
In terms of fairly straight forward use of the blocks, I recommend installing the source code and taking a look at the Quickstarts that come along with Enterprise Library. It will show many common scenarios, how to use the block and how to set up the configuration. Some of the scenarios will have integration aspects (e.g. Exception Handling block using the Logging block).
Across most of the blocks, Enterprise Library is very flexible so that it can cover a wide variety of usage scenarios. Unfortunately, this also means that there are many ways you can use the blocks. e.g. when using the logging block you need to define your categories (what categories make sense for your application?), will you even use priority, etc. For many of these decisions there is no right or wrong or "best" answer. For many choices it could be personal preference or a specific requirement that needs to be addressed. For example, I rarely see a need for using the Exception Management Block but I can imagine scenarios where it would offer some value.