'k; so what you need to know ...
DHCP is a service that is exposed on a network segment. In your case, your Win2003 server is running a dhcp service, so if you need to change dhcp server settings, you will start there (i.e. what range of IP addresses are available, which default route to use, how long to take out a lease, etc)
In Linux, you then usually have a DHCPD service. This is the client that will connect to your dhcp server (win2k3)
Your dhcbd client will then be responsible for configuring your network interface.
You should not need to set any ip addresses. What you will need to do is find out what dhcp client is available on your system and find out how to configure that.
With Linux distributions having a windowing interface, there will usually be a network settings applet you can use. This you should usually just configure as 'dhcp' save and forget.
In my case I have a file under /etc
/etc/conf.d/net
which just has the line
config_eth0=( "dhcp" )
Then I have a service called dhcpd which is started at boot time.
Best, in the end, just google your distribution + dhcp config, i.e. "ubuntu 11.04 + dhcp config" or something like that