In the app itself from the sign in page there should be a link that says learn more you can tap that to get more information on how to author maps for data collection, that link will take you to http://resources.arcgis.com/en/collector/ where we have a few tutorials to help you get up and running. Once you've authored a map for collection, log in to the app with your organizational account and it should show up.
The biggest difference is that you need to have an editable point feature service (lines and polys are coming in a future release) in the map for it to be compatible with the Collector. If you want to share the map with me I can take a look.