Requirement for tourist visa to attend graduation ceremony

Dear Sir/Madam

I would like to attend the graduation ceremony of my child in the 2nd week of January 2013. I have a few questions which i will be glad if you answered at the earliest:-
1. What documents should I present to the embassy other than the "Invitation letter" which was just given by the College to her stating that she is a student there and I, as her father, are invited to attend it. Is this paper just enough? Which type of visa should i apply And how long is it valid?
2. Also if this doesn't work, then how can I go to attend the ceremony?
3. What procedures does she need to do from there to send me an invitation letter ( not from agents or such places) ?