"httpd: cannot determine local host name"

[André Bell <debian2@one-click.com>]

Apache tells me "httpd: cannot determine local host name. Use the
ServerName directive to set it manually."

Now I know ServerName is not something I can run from the command line
because I tried it. That means there must be something else I need to type
on the command line after typing 'apache' to define a servername(?).  

Any ideas what I've missed? The answer isn't obvious in Que's "Using
Linux".  There are four pages of stuff about DNS and IP addresses but
nothing specific to giving a host name to an Intranet or local machine.
Since they say DNS is 'notoriously hard to configure' and is used for
resolving mnemonic names that represent hosts I'm guessing it's not the
tool for giving a name to my local host. 

How do I give my local machine a host name?

Andre'
BTW, is there a good book for debian and packages which may be unique to
debian?