Whilst on a project that involved building several SharePoint farms, I wanted to complete my documentation with the actual layout and build of the farms.
During my research of documentation tools, I found a very useful and free way to get an inventory for your SharePoint 2007/2010/2013 environment using a PowerShell script written by James Hammonds, on TechNet:
To run the script, you first need to load into memory using “. .\Inventory-SPFarm.ps1”, note the space between the two periods, then run:
Run-FullInventory -LogFilePrefix "TestEnv1_" -DestinationFolder "C:\Docs"
This will produce a series of CSV files with the details of your farm. Be careful which drive you output to, the article does warn it can produce large log files.