A letter of invitation from your school stating that you will be graduating. soem schools will give out pass/tickets for commencement.. ot the International advisor's office will write a letter.

Just that letter and your i-20 from here..plus if you have a GPA 3.5+, i guess it wont hurt if you send your transcripts as well. but if your gpa isnt too good, dont botehr about the transcript...

For your parents, ask them to get a bank statement..."official" letters confiriming your dad's current occupation, mom's occupation..etc and you are all set.