[dnanian]

I've posted this before, but to repeat:

* Start Disk Utility
* Select the external drive hardware in the sidebar
* Click the Partition tab
* Use Disk Utility's controls to divide the drive as needed. Use "Mac OS Extended (Journaled)" as the format type and name appropriately
* Click Options
* Choose the proper partition scheme (GUID for Intel macs, Apple Partition Map for Power PC) and accept the page
* Click Partition.