Question : setting up a metropolitan area network

how do i build and set up an efficient, secure and reliable local area network and metropolitan area network and what exactly do i need? thanx.

Answer : setting up a metropolitan area network

This question is extremely broad.

I've thought about it, and thought about it, and theres no simple way to answer it.

For a local area network, it depends whether its home or office use.  How many computers are in the office?  Or in the home?

Are you segmenting the network by department.

There are so many areas to cover, be it collision domains, broadcast domains, network segmentation, subnetting, its next to impossible to answer.

You're best bet is to get a network designer to talk you through it.  I could certainly make suggestions, but its entirely dependant on what you need to do with the network