Windows PowerShell and SharePoint Commands

go to Windows Powershell located at

%SystemRoot%\system32\WindowsPowerShell\v1.0\powershell.exe
you can also reach here from Accessories>WindowsPowershell

Type following command
add-pssnapin microsoft.sharepoint.powershell

you can verify by typing following command
get-command -noun sp*

this should return you thousands of commands available.