Networking Assignment – How to build a LAN

I need detailed notes on how to Construct and maintain a simple Ethernet network and an IT infrastructure for a company with minimum 25 computers. Define the type of network and discuss the application of OSI layer at different level in detail while building the network. Identify the role of TCP/IP system relate to local area network and the Internet. Describe the role of business and recommend appropriate software and hardware and justify your decision.(2000 to 3000 words)