More than ever, admissions officers are inclined to place a phone call to a recommender for more details. Don't use references from friends or relatives, or recommendations from people who do not know you well. Give your recommenders all of the necessary forms, plus addressed, stamped envelopes. Give your recommenders at least a month in which to write the reference and ask them to meet a deadline. Let the recommender know when you will submit your applications so he or she can send the reference letters at the same time.
Reference letters can be confidential or non-confidential.