We'll want a copy of the prior year's tax return. We'll also want your W-2s, 1099s, 1098s, K-1s -- all the things you've received that say "Important Tax Information." Additionally, you'll have to provide information on revenues and expenses from your small business and/or rental property activity if those apply to you. Filling out our tax organizer is most helpful. In fact, we now insist upon it.