Any server admin's out there?

[VoodooDali]

I need help picking out a server for my business.
It will only have 5 users max.
3 users are in a different state and need remote access.
I plan to run MS Small Business Server 2003 along with Office 2003 Pro, and will potentially use this with MS Sharepoint to collaborate on files and databases.

I'm confused about a lot of things -
do I need 2 CPU's or one?
P4 or Xeon?
2 hard drives or one?
how much RAM?
some offer a video card - but my company does not use any graphics software and it won't run games, so is this necessary?
Is MS Exchange Server a different piece of software or redundant and unnecessary when you have your own server? (We currently pay for hosted exchange server)
What do I need to know about my business' website in order to run it off the server (e.g. do I need to know how big it is? how much bandwidth it uses?)

How hard is it to maintain your own server? Do I need to take a course?

[Rookierookie]

2 CPUs are WAYYYYYYYYYYYYYYY overkill to have dual Xeons. Even a newer Sempron or Celeron will be enough.