I have finished re doing our home network, the Mac was replaced with a Gaming PC and we all have Netbooks so the shared computer is not used that much now. Lets see your network.
The Linksys WRT54G router, i forgot to edit, I have a DGL-4500 dlink. I also don't have a HP netbook, I have a Acer netbook.
Our network started with 2 computers connected with a crossover cable... The network wired up as logically as possible, the main devices connect in to the 8 port gigabit switch. Wires run around the outside of the house to network wall points in each of the rooms listed above. A switch is then connected to the wall point if more than one device is in that room. We don’t really use wireless, its disabled 99% of the time unless the DS or PSP need to go online which is hardly ever. If the laptops are ever used at home they usually just connect to the switch in the living room.