You need to think and pray about what is best for your situation. There are many, many examples of what should go in a 72-hours kit. Here is a general list to at least look at:
http://lds.about.com/od/preparednessfoodstorage/a/72hour_kit.htm
http://lds.about.com/od/preparednessfoodstorage/a/72hour_kit.htm