Doing a clean install of 9.10

[Nigel Ridley]

So after reading that some on the list had problems with their upgrades, I've decided to do a 
clean install of 9.10.

Not wanting to wipe my [separate] /home partition - how do I know which _is_ my /home partition?
This might sound like a stupid question but there used to be a time when /home was on, say, hda5; 
nowadays with all this uid (or whatever it's called) there is no hda5, hda1 etc. only [stupid] 
unrecognizable too_long_for_humans_to_remember numbers!

So how do I format /root and not /home?

Blessings,

Nigel