I would take a look at the Linux Documentation Project's Network Administrator's Guide. It's available on line at www.linuxdoc.org.
It's an excellent source of information.
But aside from that, try the ifconfig command. That will do the job for you.
# man ifconfig
for all the gorey details. However, that command does not permanently configure the adapter, so you also need to edit a config file.
There's an Ethernet adapter config file in /etc. It's in /etc/sysinit... I don't remember the exact location. Sorry I'm being so vague, but I don't have access to my Linux systems or manuals right now. Anyway, that file is used to set config parameters for your adapter that will be applied on startup. Where's the file? Answer to that would be in the Network Administrator's Guide.
Of course if you're using Gnome or KDE, there's some graphical tool to do that for you.