Netgear GS108 works great to connect up those devices around the house or small office. Around $70.

A million different NAS devices out there.... Make sure they support mirrors(Raid 1) or Raid-5.

Raid 5 means you will need 1 extra drive, Raid 1 means you need twice the drives.
(so, using 500GB Drives, you need 3 for raid 5 1TB, 4 for mirrored)
(using 750GB drives, 2 mirrors yield 750GB storage, 4 for 1.5TB. Raid 5, (min 3) so 3 for 1.5TB.

If you want quiet, stay away from ANYTHING rackmountable. The gear is nice, but always loud and always expensive.

Even with raid or mirrors, don't forget about backups. On any particular device, ask yourself "What if this device got destroyed. How would I feel".