Handling federal income tax withholding?

[RDecker]

I've searched the forums but found nothing with "income tax" or "withholding." Can anyone offer any suggestions as to how to go about setting up federal income tax deduction calculation? I'm not an accountant, and looking over the "Employer's Supplemental Tax Guide, Pub. 15a" (from the IRS web site) it looks straighforward, but implementing it is another matter. There are 7 possible percentages based on income, each with an accompanying exclusion amount. (Of course there is also the question of filing status and pay period! But for now, let's keep it simple and assume, say, married status paid weekly.)