#!/usr/bin/env puppet

# in $modulepath/ntp/files/
./client-ntp.conf
./server-ntp.conf

# in $modulepath/ntp/manifests/init.pp
class ntp {
    package { ntp: ensure => installed }
    file { "/etc/ntp.conf": source => "puppet:///ntp/client-ntp.conf" }
    service { ntpd: ensure => running, enable => true, subcribe => [Package[ntp], File["/etc/ntp.conf"]] } 
}

# in $modulepath/ntp/manifests/server.pp
class ntp::server inherits ntp {
    File["/etc/ntp.conf"] { source => "puppet:///ntp/server-ntp.conf" }
}

# the 'all' class
class all {
    ...
    include ntp
}

# your ntp server:
node myntpserver inherits base {
    include ntp::server
}