Sharing files/printers on network with wireless/hard wired computers

I'm trying to configure the network of a client of mine but am having some difficulties relating to file and printer sharing. He has about 5 PC's and 2 laptops connected to the network via a wireless D-Link router. He has a cable connection, not DSL. All the PC's are hardwired but both laptops are wireless. The Internet works fine on all the computers. The issue is that all the hardwired computers are seeing each other and sharing files just fine, but the wireless laptops are neither seeing each other nor any of the desktops. The desktops don't see the laptops either. When I try searching for any of the desktops from the laptops, they're not found, nor vice versa. I've tried running the network wizard numerous times on all machines, enabling file/printer sharing in the process, but no luck. Speaking of which, when I'm running the network wizard on any of the computers, which one of the following options should I select, based on the physical configuration I've outlined above:

"This computer connects to the Internet through a residential gateway or through another computer on my network."

"This computer connects to the Internet directly or through a network hub. Other computers on my network also connect to the Internet directly or through a hub."

Or should I simply skip this screen by selecting the recommended option of using the current Internet connection?

Secondly... should I click on "Setup a home or small office network" OR "Setup a wireless network for a home or small office" when setting up the laptops?