If your organization doesn't have an ArcGIS Online subscription yet, sign up for a free 30-day trial. You can invite up to five named users to participate in the trial, and you get 200 service credits. You also get a number of productivity apps as part of your trial, including Collector for ArcGIS, Operations Dashboard for ArcGIS, and Esri Maps for Office. Once your trial is over, purchase a subscription and continue to use all the features and services in the same ArcGIS Online subscription account. To sign up for the trial, go to esri.com/agoleval.
See also "ArcGIS Online: What's New".