Assuming that you are using Micorosft Windows DHCP server…
Open the DHCP manager
Connect to the DHCP server
Open the Server, then the scope
Right click on Reservations and select “New Reservation”
The Reservation Name is usually the name of the server. The IP Address is the IP address within the scope you wish to reserve.
The MAC Address is the MAC Address of the machine who will be using the reservation.
The description is optional.
Select DHCP, BOOTP or both depending on what services you are needing (some very old devices will only utilize BOOTP, which is older than the DHCP protocol) and click Add.
The “options” typically configured are:
6 – Router or Default gateway
15 – DNS Servers
44 – WINS Servers (optional after windows 2000 in an active directory environment)
46 – Netbios Node type (typically, 0x8 is the default and almost always good to use.)
While there are others, typically these are the ones most commonly used and will get you off the ground.