Hi there,
one of the problems with Gigabyte's BIOS is that they show SATA devices as IDE and it gets very confusing. Don't worry, when you plug them in and start up your PC they will be shown under the heading Standard CMOS Features.
However, I would recommend only installing one of your hard-drives and one of your DVD Drives in the beginning. Install your OS then add the other Hard drive and DVD Writer once you have finished that process. If you are going to install Windows or Linux it should find the Hard drive automatically. In the first instance hit the F12 key during the BOOT process and highlight the DVD Drive as your first BOOT Device. You can safely change this back to HDD once you have installed your OS although you shouldn't really need to.