Business set-up

[Camelcase]

I'm tasked with setting up a network. I'm doing research as I go and I feel like I need other peoples advice. My network needs at least 20 computers with room for expansion, it will need at least 20 email accounts, web hosting, and of course internet access. What do I need all together?
Can I use multiple switches?
Do I need a router?
What hardware do I need?
How do I set up an email exchange server? does the email server need to be separate from the original server?
Can I use one server for both email and roaming user profiles?
What cables maybe needed?

I'm asking a lot of questions because I want to see what input anyone can put in. I may know most of what I'm looking for but I want to see if there's a way I can do it better and more cost effective.

Thanks!

 

[riser]

Exactly what kind of research did you prior to posting this?

 

[Camelcase]

Exactly what kind of research did you prior to posting this?

Pricing, different topologies, OSs, NOSs, cabling. My research is at a stop because of email servers and set up of the email servers.

 

[ngrego]

All the information you need is depending on the work you will be doing at this business.