Kanas Withholding Tax Guide
this is an exellent guide I found, even shows you the steps of how to manually figure the taxes.
IMO if you are running a small non-profit business I would recommend some bookkeeping software such as quickbooks to help you manage your business. Tax laws for non profit business may run differently than the other business classes.
Also you should have already recieved all the forms and which forms you are required to fill out plus your payroll tax coupon booklet.
If ya need some help just hollar.