Documentation varies depending on how you are applying for residency.
In general, unless you are applying for E-1 or C-3 residency or through one of the military exceptions, you must submit a completed and notarized Request for Resident Classification.
The Request for Residency Review packet is available from Undergraduate Admissions for undergraduate students or Graduate Studies for graduate students. Forms are also available online.
In addition to the Request for Resident Classification, you must submit documentation for all sources of income used during the 12-month period you have been trying to establish residency.