Designing a network

I am a new IT officer in a company, where I have been given the task of setting a new Network. The network is to be based on windows 2000 server with around 50 users, an application using oracle 8i, facility for internet browsing and email account for all the users. Now the problem is that I have been asked to submit a network proposal to my managment whereby I should give a detailed step by step implimentation. Such as
1. Cabling (layout and design)
2. Hardware and SW req.
3. Step by step setup plan (defining the user rights and IP allocation and what to install at what stage and so on)

Can someone help me ?