Can't connect 2 Macs wirelessly but each connects to Internet

I have two Macs that successfully share an Internet connection but cannot connect to each other wirelessly. Both run OS 10.4.11. My iMac is wired to a D-Link router (DI-524). My Intel MacBook connects to the router wirelessly. I want the MacBook to access files on the iMac wirelessly, but I can't get the MacBook to connect to the iMac (Go > Connect to server just churns). There must be something simple that I'm missing in how the network is set up. Thanks for your help!

Do you have Sharing enabled?
Set Up File Sharing in OS X 10.4 (Tiger)

Personal File Sharing is enabled. Sharing Preference gives an address for access by computers on the local subnet, but that doesn't work. However, I'm not sure the 2 computers are on the same subnet - perhaps because one has a wired connection and the other a wireless one. The IP addresses are 192.168.15.2 (iMac wired) and 192.168.0.107 (MacBook wireless), both with a subnet mask of 255.255.255.0. They list different router addresses, too.

Sharing Preference also gives the IP address of the iMac and says other computers can access this using afp, but the MacBook just churns when I try that.

Thanks for your help -

Yeah, you're running two different networks:
192.168.15.0
and
192.168.0.0.

Think of them as two different rooms - your Macs can't talk to each other that way. You should be able to bridge them though.. check the options on your D-link...