Documentation

Document Your SharePoint Site Using PowerShell
http://technet.microsoft.com/en-us/library/ff645391.aspx

Using Visio to Document your site (thx Wayne)
http://iedaddy.com/2011/11/sharepoint-information-architecture-diagram-using-powershell-and-visio/

Farm Document Tool from Codeplex
http://spsfarmreport.codeplex.com/

$ SPDocKit – SharePoint Admin Kit – Checkout The Free Eval
 https://www.spdockit.com/