http://www.Gridcoin.us is the main website for Gridcoin and has many informational links. https://www.eobot.com/faucet will give a small amount (1/2 a cent USD) of GRC daily if your account is set to mine GRC and you use the faucet. You can also cloud mine Bitcoin and be paid in GRC on EOBOT.com. They have a 200 GRC minimum before you can transfer it out.

For small amounts of free coins you can try visit:
http://www.gridcoin.ch/faucet.php
http://uscore.net/
https://gridcoinstats.eu/faucet.php