Hello Cindy,
Thanks for your posting and your interest in TestRail. We usually recommend using the Milestone field for test runs/plans to track versions/releases. The Versions field on the Add Test Result dialog is just an additional field to track specific software builds and/or other smaller updates.
If you are using the Milestone field, you have a variety of options for reporting, e.g. by going to the overview page of the milestone (Milestones tab in TestRail and then select the milestone in question). You will find Status, Activity and Progress reports on this page. If you need more details, you can create many different and more detailed reports on the Reports tab, e.g. for comparing test runs over time (comparison/coverage reports) or finding the defects for specific test runs. Most reports can be limited to a specific milestone or the test runs of a milestone and this is the recommended approach to create reports on the milestone level.
If you want to keep using the Version field, I would recommend adding the Version/Version All column to your test tables to quickly see the versions for your test results. This looks as follows:
http://blog.gurock.com/wp-content/uploads/2012/04/columns-large.png
(Just click on the column icon at the top-right of case/test tables to open this dialog)
I hope this helps and please let me know in case you have any further questions!
Regards,
Tobias