This script is identical to my previous Simple XCopy Backup Script, except it uses the new robocopy command that comes installed on Windows Vista, 7 and 8.

@echo off
:: variables
set drive=E:\
set backupcmd=robocopy /mir /z /fft

echo ### Backing up Documents...
%backupcmd% "C:\Users\ENTER USERNAME HERE" "%drive%"

echo Backup Complete!

The difference between xcopy and robocopy is overall performance. Robocopy can tolerate network interruptions, has built in bandwidth throttling, and can copy multiple large files that could otherwise crash XCopy. You can read more information on Robocopy on Wikipedia and Microsoft TechNet.