Keep in mind that depending your your situation and circumstances of the requested mortgage you may be required to furnish information in addition to what is listed below.
Verification of income(possibly including but not limited to.a pay stub
Last 2 years W-2 and 1040 form
Last 3 months bank statements
Names, addresses, account #'s and details of your long-term debt (credit cards, auto loans, child support, etc.).
If you're self employed you may also be required to provide financial statements for your business.