In most cases it shouldn't be necessary to configure anything before building.
If you do want to make configuration changes, it is recommended that
you start by going to the xc/config/cf directory, and copying
the file xf86site.def to host.def. Then read through
the host.def file (which is heavily commented), and set any
parameters that you want for your configuration. You can usually find
out what the default settings are by checking the .cf file(s)
relevant to your OS.
A general rule to follow is to only change things that you understand
and have a good reason to change. It is easy to create build problems
by changing the default configuration. Many of the configuration
parameters are documented in xc/config/cf/README.
If you are using just the X430src-1.tgz,
X430src-2.tgz and X430src-3.tgz parts of
the source dist, you will need to define BuildFonts to
NO.