When preparing the import file for donation gifts, the key item that needs to happen is the proper mapping to the Patron Record. Identify that field and ensure that when the Patron record is imported, that the field can be used to map each donation gift to the patron.
Never delete any data. Just move the column to the far right of the spreadsheet, just in case you need to reference that data later. If there is any data in the end that looks like notes, comments, dates, or just references to other data, then move it into a notes field. This at least leaves a trail for the client to reference in the future if they need be.
Donation columns: MKT_FIELD_1,DD_FISCAL_YEAR,DD_PROGRAM_YEAR,DC_CAMPAIGN,gAccount,DC_GM_SEQ,DD_DONATION_DATE,DD_AMOUNT_PLEDGE,DD_AMOUNT_ACTUAL,PAY_TOTAL_PAID,gDonor1Field,gDonor2Field,gDonor3Field,DD_NAME_OF,gPaymentMethod,PAY_CARD_NO
Excel calc to determine fiscal year: =IF(MONTH(D2)>=5,YEAR(D2)+1,YEAR(D2))