Remote Connection help

[Decrypter]

Hi. Hope someone can help.

I need to connect to my company computer. I want to do it remotely. I have one main server computer ,where I can add E-mail addresses etc, and many other computers which my staff use.

Am I correct in saying that if I remotely want to connect to the main server PC all I need is the IP address or the hostname. Then just login from there.

Also, my staff have IP addresses like 192.168.x.x. If staff want to access their computer how do they do that?

Thanks for help