On-board sound is usually okay, not great but okay, the sound quality will also have a lot to do with the speakers you're using. The volume icon can be placed in the systray by going to Control Panel > Sounds and ticking a little box in there which says "Place volume icon in taskbar". When it appears, make sure you have nothing set on mute in the settings. The headphones should be inserted into the (usually) green socket at the top of your sound outlet.
As for the IBM drives, IMHO, you should take them back and exchange them for Maxtor, Western Digital or Seagate drives. IBM drives are notoriously unreliable.