Editor’s Note: This article is part of our 2012 Tax Tips series. Robert Flach is an expert with almost 40 years as a tax professional and also blogs as The Wandering Tax Pro.

NEW YORK (MainStreet) – You may think that hiring a tax preparer allows you to forget about the legwork involved in your taxes, but to get the best refund possible, it’s the taxpayer who needs to provide the right materials.

Start with all copies of all W-2s, 1099s, 1098s and K-1s from all sources. Make and keep a photocopy of your W-2 forms, as you may need them for college financial aid or mortgage applications or a variety of other reasons.

Next, you need to put together a detailed list of itemized deductions, rental income and expenses, self-employment income and expenses, and child-care expenses. Your tax pro doesn't need to see the individual bills, receipts or canceled checks; a detailed list or worksheet with the numbers will suffice.  

And when we say “the numbers” we mean the specific numbers. “Claim the maximum” or “whatever I am allowed” or “same as last year” won’t cut it.  The maximum is what you actually paid in taxes – and you are allowed to claim only what you actually paid!

It is rare that an item on your return is exactly the same as it was the previous year. Tell your tax pro “$1,023.50” or “$20.00 per week for 50 weeks” or “4,638 miles.”

It is important to include the Social Security or Employer Identification Number for all child care providers. Just writing “Sam” will disallow the credit for child and dependent care expenses if you do not provide an official identifying number on the Form 2441.

Your preparer will also want all year-end statements, reports, booklets and other literature you get mailed from brokerage accounts and mutual funds. The statements will contain details on cost basis, purchases, dividend reinvestment, margin interest, management fees, and booklets often include information on income from government obligations useful in preparing your state return. I also ask clients to give me the final pay stub for the year for each employer.

Although it may sound basic, you should provide the dates of birth for yourself, your spouse, and all dependent children. There are several reasons why this information may be important.

If you’re filing your taxes for the first time this year, make sure to check out MainStreet’s Taxes 101: A Beginner’s Guide to Filing Your 1040!