I think Rasbian removed the whole default raspi-blacklist.conf file sometime ago. Instead of editing the /boot/config.txt as suggested by Stabby.
The better way of doing it without going to change the file is use raspi-config to change the setting for you.
sudo raspi-config
Then select
advance options
Select
A6 SPI Enable/Disable automatic loading
and say yes to all the options.
You can also enable i2c here. reboot the system and you should see spidev0.0 and spidev0.1 in dev