A bank's primary concern in considering you for a home loan is your ability to repay. Before giving you a loan, the bank requires documents that prove your income and assets. These documents let the bank know if you can afford the payments.

W-2s

If you are employed at a wage-paying job, you receive a W-2 form each January. The form tells how much money you earned at your job in the past year and how much you paid in taxes. You will probably need to bring W-2s for the past two years.

Tax Returns

If your are self-employed or have income from sources other than a job that provides a W-2, you need to provide income tax returns for the past two years. This allows the bank to verify your income and expenses.

List of Assets

The bank may require the last two months' bank statements. Include statements for your checking and savings accounts, as well as statements verifying any investments (CDs, IRAs, mutual funds, etc.). If you own any vehicles or real estate whose loans have been paid off, the bankers may also want to see the titles.

Employment Pay Stubs

Some banks require pay stubs in addition to W-2 forms. The pay stubs tell how much money you are paid with each paycheck and prove to the bank that you are employed.

Evidence of Debts

Debt information includes credit card statements, proof of alimony or child support payments, evidence of mortgage or rental payments or paperwork involving any other regularly recurring debts. The bank compares this information to your income to figure how much of a debt load you can take on while remaining in a position to repay it.

Source:

Mortgage-X.com: Loan Application Checklist