Your interviewing portfolio requires several things. Among them are: your resume, a list of references, paper and pen for taking notes, a list of questions to ask the interviewer, and a sample application.
If you have never completed a job application for yourself, I highly recommend that you do. Download and print the LA SF-10 (http://www.gohsep.la.gov/agencyrelated/forms/sf10.doc) and complete it thoroughly with every job you have EVER had, including volunteer activity. Note all of the dates, contacts, reasons for leaving, etc.
This will ensure that you don’t have to waste time scrolling your phone for contacts and “Googling” business names and addresses when you are asked to complete an application. Consider it your handy reference.