PowerShell v.2 allows your functions to seamlessly integrate with the built-in PowerShell Help system. All you need to do is a Comment-Based- Help block into each function:
A useless function
This function really does nothing
Demonstrates comment based help
Test-Me "Hello World"
Once you run this function, PowerShell will know where to look for Help, and you can use the built-in Get-Help to display the information in pretty much the same way as it already works for cmdlets:
Get-Help Test-Me -examples