Domain Management

Question

Hi friends,

     I'm going to buy dedicated server for windows hosting. i have lot of doubts to clarify, my questions are following...
    
     1. what are all the basic service i have to check before buy?
     2. what about OS and Database license cost?
     3. what about Control Panel?
     4. Can i develop own control panel for managing domains?, or have to buy any tools?

I'm in need of clarifications, so please guide me.
Thanks in advance.