1st Time Bios Setting

Building my 1st daw, an i7 920 on a Gigabyte ex58-ud4p, xp home 32bit, and am a little unsure about what to do on 1st power-up. Can I use the stock bios settings and pretty much not do anything, or are there some things I should change for a daw. There also seems to be a 'failsafe' default and an 'optimized' default on this board, no idea what that means. Any info or links would set my troubled mind at ease before I lose my cherry.

Always go stock at first and make sure everything works.
Boards are very good at CPU settings but sometimes do not optimize memory correctly so your first chore after testing with stock settings should be to check the memory timings with the specs for your particular memory and manually adjust if needed.
That's all the 1-5-13-12-15 etc stuff FWIW.

After that, if you are interested in toying with overclocking, try the pre-set OC BIOS settings first and see what happens.

It goes without saying that a decent cooler should be used if you plan on anything radical.

After that, check some of the groups for known good settings and try them.

Minor overclocking usually works fine but I would not suggest radical, or anywhere near radical settings for DAW work.
It's not worth the performance vs stability gains.

You should find that if you have selected compatible hardware and connected it properly, the Gigabyte bios will run through POST with default settings. The Gigabyte EasyTune software has some nice overclock "presets" that you can test out and work pretty well though I found that DPC Latency was increased on my machine while EasyTune was running in the system tray. I found it best to set in BIOS and not run EasyTune in the tray.

On the onboard sound card, it depends is the real answer. Some have no issues with the onboard enabled, others have issues. I'd wait and see myself. In my case, I have no issues with onboard enabled, but since I don't use the onboard card, it's disabled.