well, as far as screwing up...
abit has a flash utility and it is like, find file, click flash. bingo bango, no problemo.
but, i was a little tense the first time as well. i read about abits flash utility that came with my mobo, and if it encounters any problems, it discontinues the flash (basically it waits to erase the old until it knows the new will work, i guess?), so it was no big deal. but that utility was made specifically for that motherboard. using a third party bios flash program, errr...i dont suggest that. you can get a cheapo ext. floppy and backup your current bios. then flash the new. i'd just leave it alone.
it is pretty likely you will be like.."DOH!"...