I've been looking at acquiring something like the Maxtor Shared Storage Plus 500Gb HDD for our mini home office (2 PCs). We're currently running the network through a D-Link DSL 504-G (both PCs have software firewalls).
If we use our DSL router to join the shared storage to the network, are we exposing the network to additional security weakness? How can we keep the network secure while adding shared storage?
The DLink DSL-504T is also a router. So it has the basic set of security features like NAT Overloading and Port Forwarding. You mentioned you have a "504G". I looked on DLink's site and didn't find any information on that one, but I suspect it's probably the same.
In that case, you can rest assured knowing that any network storage you add will be safe, behind the router and away from the "dirty" internet.