...
It's been a few years since we installed a home network, but that is usually typical ...install and forget these trouble-free devices. You'll be buying much newer equipment than we have.
I like to use Office Depot (
http://www.officedepot.com/ ) or Staples (
http://www.staples.com/ ) as local suppliers since they have even been cheaper than many websites in the past. Their stores often carry much of what is shown and described on the website.
Newegg (
http://www.newegg.com/ ) is a reliable and economical web order site and has a comprehensive customer review database and a good information knowledge base to boot,
(
http://www.newegg.com/Info/KnowledgeBase.aspx )
leading to off-site help such as
(
http://www.pctechguide.com/63Networking.htm ).
Besides the router you will need a Wireless-G USB Network Adapter for each computer. Some laptop adapters are very small and plug into the side or are built in by factory. Make sure they are compatable frequencies such as G that is now most common. Most routers will handle several computers but there is a limit so make sure you're covered. One computer next to the modem which will plug directly into the router (LAN) can probably be plugged in turn directly to the router, also via LAN cable. You can run other LAN cables if it is easy to find a physical path since most routers also handle several non-wireless LAN connections. LAN connection jacks are very common even on older computers and look like oversized telephone jacks. Most routers will reach throughout your home without a booster and possibly to the neighbors if you don't specify security during set-up.
Good luck.
...