Importing into an address book-Domino/Notes

I am running an Domino mail server. We have the standard address book that is created, but would like to have a new one that I can populate with email addresses of students and parents, so that staff can create groups based on this. I was told that I could take the names template and import the information into it and it would work. To date I have not been able to import information in, and I do not relish the idea of putting in over 500 email addresses. Does anyone have a suggestion?