Implementing client/server network

I need a barebones plan for designing and implementing a client/server network with 10 workstations, and a growth potential for 10 to 20 additional workstations. We are now using a peer network that isn’t working out very well, because we are using older computer hardware and a mix of Windows 98 and Windows XP operating systems. The new network will have new computers and wireless technology. Can you direct me to resources on the web that will allow me to research and design a suitable network?

Thanks,
FrenchFries