I am going back home this winter after 7 years. I need to get a new passport and visa. Although I am a graduate student with funding, I am wondering what documents are needed to get new visa. how long does it get visa stamped and passport? Do I need to show financial documents like i did when I came for undergraduate.
Thanks.

Applying for visa is same as if u were applying for the first time. You need to show all financial documents including funding u mentioned from the college and the tie to the country which could be property valuation details of ur parents. You might also wanna show your payslips and tax returns...
Getting new MRP will take couple of months thru normal processing and a week thru expedited processing. Getting visa is up to the US embassy and might take from a week to couple of weeks to get the appointment date depending on the month.

i was in same situation last year and renewed my visa. you dont need lots of things. i just took my i-20, letter of enrollment, my transcript, and letter from mu department saying i get funded. that was all.