It’s not as well known as it should be, but there’s a great source of documentation for the ifcfg-<interface> files that provide network settings in some configurations. NetworkManager has the ability to interpret these settings as well.
If you look in the online documentation for the initscripts package, you’ll find a file called sysconfig.txt that has a listing of all the parameters in ifcfg files that are parsed by your system’s startup (init) scripts. This can be really helpful when you have to write a network configuration file from scratch, or you want to know what the legal values are for a specific variable. For instance, on my Fedora 15 system, this file is found at: /usr/share/doc/initscripts-9.30/sysconfig.txt
Hopefully this information is helpful to some readers, since it came up today in a conversation with someone at Ohio Linux Fest whom I consider to be highly skilled and educated sysadmin.