On the number of HDDs present in a system

[invisiblesurfer]

I have a EX58-UD3R (v. 1.6) which I have not installed OSX on yet (running winblows atm - don't flame me).

 

I have 1 DVD-R device as well as 2 HDDs (120 + 500GB).

 

120GB HDD -> SATA 0

500GB HDD -> SATA 1

DVD-R -> SATA 2

 

Is this connection correct for booting OSX off the 120GB HDD?

 

At this point win7 is installed in the 500GB (I explicitly instruct the bios to boot from that drive first). Is my installing OSX on the 120GB drive will automatically allow me to dual boot?

 

Thanks in advance, I am a bit concerned that messing up the HDDs might ruin my instalation (which I think is going to be Kakewalk -but I'm open to suggestions).