I think the advice you have been given is correct - I'm assuming the DG834G has multiple RJ45 LAN connectors. Just run normal Ethernet RJ45 Patch cables between the Router and the PC's. You can then share the Internet connection. It really is that easy.
When you get round to the Wireless connection (for the laptop) you will find that should be fairly straight forward - you need to set the SSID, Channel and WEP encryption but that isn't difficult and the Netgear will take you through the steps. Before you finalise the WiFi check on any other wireless networks close by and select a channel that doesn't conflict. Good luck.