Sharing a Printer on Wireless Network

I am trying to create a wireless home network, I have a DSL modem that is hooked to a Dlink DI-624 wireless router and a cable from that to a Tower XP Pro computer, other is a laptop XP Media Center,which connects wirelessly. Both computers connect the internet fine, but when I try to view the network, can not ping either computer or the gateway? Both computers are in same workgroup, I have “bridged the connection’s on wireless laptop, but can’t on tower as there is only one connection? Any ideas on how to make this work is there something I’m missing. Thanks for any ideas.