(continued)
If you are new to this whole networking thing, I would suggest looking at a couple books in the "XXX for Dummies" series, specifically
"Networking for Dummies" (make sure you get the latest edition). This will give you a broad overview of the various network operating systmes available as well as general hardware requirement guidlines. The series also includes a few other networking books that are more focused (i.e. Cisco Networking, Windows NT Networking, Home Networking, Small Business Networking, Windows 2000 Networking, Networking with Netware, etc.). I recommend this series to people just starting out in a given subject area because the writers manage to get across the necessary information, without a lot of technical jargon, and managing to inject some humor into what is usually a very dry subject, all within a concise inexpensive book.
It really pays to sit down up front and determine not only what you want to be able to do know, but also where you think you might be 6 months or 1 year down the road. This will help you accomplish 1 of 2 things: implement a solution than can be expanded to meet growing requirements when your business starts booming down the road; or keep you from implementing way more network than you will ever need.
Good luck, I know networking can be a daunting task if you are new to the subject.