D-Link DWL-900AP & Speedtouch 510v4

I have just acquired a d-link WAP (& d-link) pci card to enable a 2nd pc to
use adsl via my Speedtouch 510 modem/router which is connected to my main pc
via an ethernet link.

Dumb question, but is it possible to use ICS (both machines running XP Pro)
to share files/print etc between the 2 pc's using the speedtouch? I am a
little confused as to whether I need another router/hub etc or a 2nd wifi
pci card in the main pc?

Thanks for any help (again!)

Mark