With a normal 2 NIC + router setup for SBS 2000, the router is in a separate
subnet from the SBS (LAN) network.  Therefore, the wireless router is
outside of your SBS network.  Workstations attached to your SBS network can
acquire IP addresses from the SBS server and can get to the Internet because
they go through the SBS server (and the external NIC).  So, since your
wireless router is outside of the SBS network, any wireless devices that try
to access the wireless portion of the router will also be external to your
SBS network.  By turning the DHCP service ON in the router, wireless devices
will then be able to get an IP address from it and access the Internet.

However, wireless devices will not be able to directly access, log into or
be part of the SBS network.  If you need this capability, you'll need to
install a Wireless Access Point (WAP) inside your SBS network - attach it to
the same switch that the SBS server and workstations are attached to.

Internet

Wireless Router WAN

Wireless Router LAN - Wireless devices attached

SBS External NIC

SBS Internal NIC

Switch

Workstations