@alama56

School records means - your attendance record, transcripts, letter from DSO, no need to send I-20

@nsb
1) ask your school to write a letter that you are taking classes during summer, if possible ask them to mention your attendance record .(letter from your school should be good enough :)
2) tuition and class schedule should be good.
3) yes, just print the back documents that will cover the june and july- ie from june 6 to july, or june 1 to june 30 and so on..
4)send medical insurance card, it should have your a start data, if not then send that whole agreement from your insurance.
5) I am not sure about photo, as people are telling about it , send the photo too..
6) any grocery receipts , online purchase, if you have changed your address recently then letter from USPS, if you have rented a car then car receipts..

if you still need more info, let us know what documents you are planning to send and we will let you know..

and yeah send your documents with a tracking number.

read the following document, won't take more than 5 minutes, you will get an idea what documents you need to send

http://www.uscis.gov/sites/default/files/files/form/i-821instr.pdf