Sorry for your loss...
As your father was a NY resident - total estate is a subject for NY estate taxes.
New York decided to discontinue its estate tax's link to the federal estate tax, which is being phased out - thus New York estate tax liability will generally exceed the allowable federal credit for state death taxes. The estate must file a New York State estate tax return if
NY estate tax publications - http://www.tax.state.ny.us/pubs_and_bulls/publications/estate_pubs.htm
please find NY forms here - http://www.tax.state.ny.us/forms/estate_cur_forms.htm
To calculate NY estate tax - you need to file an estate tax return and take all deductions.
Only the amount above $1,000,000 will be taxable - see tax schedule on the last page of the form - http://www.tax.state.ny.us/pdf/2008/et/et706_308.pdf .