Right then, firstly the WAN link - this depends where you are? if you are in the UK you could go with a company like aaisp and get 4 of their maxDSL lines and bond them together to get a decent link, or rent an SDSL link.
Router wise, a decent (80+ £) one should do, maybe look to get a cisco 837/857/877 as they are pretty nice bits of kit and can do a hell of a lot of stuff (QoS and the like)
Switch wise - get a single switch that has enough ports for the entire place, it is better to have 1 large switch than to have two small switches linked together.
I would get a managed switch just because it allows you to see what is going on and find bugs easier, and of course a NON blocking gigabit switch would be the way to go. Jumbo frames not really needed but could be a bonus.
Linksys/Dell/HP all make decent switches == Cisco too, but they will be rather expensive.
Cables : use standard Cat5e cable (no need for cat6)
you would want it set up like this
WAN => Router => switch => PCs
the router should have a dhcpd running on it to offer all pcs on the LAN side an ip address/gateway/subnet etc as well as a decent firewall to stop anything getting in that you do not want.
PPPoE and PPPoA are determined where you are and what ISP you get.
Static external WAN IP not really needed, but if you intend for the gamers to be able to game on any server you wish, I would see if you can get an ip range from an ISP so that each PC can have its own external IP address (no need for NAT) - these would be given out by the router.
Mac Adress (Media Access Connection) : 48 bit's hexadecimal numbers all computers have a different Mac Adress
Ip Adress (Internet Protocol) : IP's 32 bits 4 "Octed"Ip's can write decimal
Public IP : For Wan
Privade Ip : For local area not for wan examples;
A Class IP: 10.0.0.0 - 10.255.255.255
B Class IP: 172.16.0.0 - 184.108.40.206
C Class IP: 192.168.0.0 - 192.168.255.255
10 0 201 32
1 octed 1 1 1 (octeds)
"00001010.00000010.11001000.01001111" =this is a binary code system
10 2 200 79
ip classes "A,B,C,D,E"
A Class IP : "220.127.116.11" between "18.104.22.168" for a class subnet mask >255.0.0.0
B Class IP : "22.214.171.124" between "126.96.36.199" for b class 255.255.0.0
C Class IP : "192.0.0.0" between "188.8.131.52"for c class 255.255.255.0
D Class IP'ler : "184.108.40.206" ile "220.127.116.11" Multi cast ip's we cannot use them "host give it automaticly"
E Class IP'ler : "240.0.0.0" ile "255.255.255.255" TEST ip's
APIPA (Automating Private Internet Protocol Adress) :
Subnet Mask : if u want to connect the same local area computers u must use the same network id's