This thread was just hilarious to read. I love how 99% of you failed to read the OP's actual question. COMPUTER STANDBY SLEEP is DIFFERENT than DISPLAY SLEEP. There are MANY ways to do this, he wants the most simple way. Anyway, thanks to the last poster made it simple and easy.
control+shift+power button is DISPLAY SLEEP
Pressing the power button and hitting S is COMPUTER STANDBY SLEEP