fdisking a disk

[justin@xxxxxxxxxxxxxxxxxx]

I have a Compact Flash disk hooked up to my DragonFly machine; I want to
give it a small MSDOS partition (~5M) and make the remaining approximate
250M UFS.

Is there an obvious way to do this?  Using fdisk and disklabel appears to
require guessing certain size and offset numbers, and I'm not too clear on
how to determine these numbers.