Do you have the router? Look on the back. If there is more than two ports, most likely there is a switch on it. From what I can tell their is a built in switch for four computers. You don't need the switch at all if you plan on connecting all of the computer's wirelessly. Make sure that those computer that you do connect wirelessly are compatible with your router, meaning that the PCI card, for the desktop if you plan on connecting it wirelessly, and the PCMIA card, for the laptop if you plan on connecting it wirelessly, are able to handle the 108mb connection. Most wireless G networks are not super wireless G, meaning they can't handle the 108mb transfer rate of the network. You wireless cards should be from Netgear and should be part of the same wireless category as your router, so they should be Super Wireless G.
I looked more on Netgears website. You should choose the 108MB products from this pages -
http://www.netgear.com/products/consumer/prod_adapter_wireless_hm.php - if you want your wireless card to work on your wireless network at the 108mb range. Use the WG511T PCMIA card for your laptop to connect wirelessly and the WG311T for you PC to connect wirelessly. If you are connecting any computer through an RJ-45 ethernet cable all you need is a network port. It doesn't matter what speed the network port is, although you probably want at least a network port with 10/100 as it's speed, so it can transfer at 100mb/s. If the network port is slower than the port on the switch it is ok, it just won't work as fast. The wireless is what you are worried about because you want your signal to be the same.
Even if your router didn't have a switch you wouldn't need an access point, you would need a switch and then you have a cable going from the router to the switch and then cables going from the switch to the PC's that you want to connect via RJ-45 cable. The think I am not so sure about is whether your router accepts a RJ-5 cable for an internet connection. From what the website says, I don't think this router allows an ADSL connection.