I don't think you need a bios update, though, you never know. What do you mean clueless? Look here for the instructions: http://www.gigabyte.com/webpage/20/HowToReflashBIOS.html
Look here for the bios (use the latest non-beta, version F9): http://www.gigabyte.com/products/product-page.aspx?pid=3894#bios
And are the cards in the slots named PCIEX16_1 and PCIEX16_2? Should be the top 2 ones.
Can you post your specs?
GPUs: 2x GTX 660