Complete Linux Client/Server Networking

You'll really need to provide a lot more information than that to get any valuable assistance: details like what hardware you have, what functionality you want (File/Print, DHCP, DNS, Web, Mail, etc, etc, etc), what software you need to run, WAN requirements, Networking hardware, and more. There are professional consultants out there who create business proposals including LAN design and configuration... for a substantial price tag.

If you want it done for 70 tech points, you'll need to offer us many more details. I'd also recommend a LOT of gratitude to the person who takes the tremendous amount of time needed to guide you through this endeavor....it could save you thousands of dollars.