When I was still living with my dad, I started off with a simple 10 Base-T LAN. It was about 5 years ago and we had just gotten Cable service via HSANet. We had his PC(in the living room) and my PC(in the basement). A 4-port 10 Base-T hub connected straight to the modem(in the basement) and was able to grab an IP for each PC. I put in a wall jack close to his PC and wired it the few feet down to the basement through the wall and floor.
A few months later, I started building PC's for myself and upgraded to a 8-Port 10/100 Switch. At one point, down in the "lair"(basement), I had about 8 Pentium II class or better PC's(a few PII's and AMD K6's and one PIII). The fastest always being my main PC, first started with Win98 and finally W2kPro. The others running Linux, Solaris i386, BeOS or *BSD. I also had a Pentium 66 running FreeSCO as a router between the modem and 10/100 switch.
Somewhere along the lines I aquired a Gateway Solo 9100 laptop. When I was in the living room, I got in the habbit of playing on the laptop and watching TV, or worked on other peoples PC on the dining room table. Needless to say, I connected a 4- port 10/100 hub to the wall jack I installed a while back.
Because I has all these PC's, my sister got in a hissy-fit. I gave her one(up-stairs in her bed room). Instead of trying to run Cat-5 through the wall 3 floors, I just ran it along the outside wall(Wi-Fi was just becoming popular and was expensive).
About this time HSANet was bought out(or whatever) by GMP and service started to suck big time. On every Sunday, no service all day. Other days of the week we had intermitent service. So we got Verizon DSL. About this time, the Pentium 66 crapped out. I found out that I could upgrade the firmware for the DSL modem to act as a router.
As time went on I started to get rid of most of my PC's. Now, I have my own place with a Linux server, my main P4 2GHz PC and Tigger's AMD Duron 900MHz PC on the 10/100 switch.