If you are using TFS 2012 then I would still question why you think you need another tool to "go agile".
I believe the latest updates to TFS 2012 have improved agile working support so this should still work just fine. You could go for Scrum or Kanban style in terms of your chosen agile working practice.
Some questions that may provoke more thought:
- Do we want to go Scrum style or Kanban?
- Which non-technical co-workers need to participate as part of the agile-style project?
- Do they all need to use TFS 2012 and/or VersionOne (or any other tool for that matter)?
- Is TFS 2012 OK to expose to the non-technical team members (who don't care about ALM tools), or do we need to bring an additional tool into play?
To be honest you could probably "run agile" on just sticky notes if that is what you need.
FYI: http://blog.countersoft.com/2013/03/basics-of-running-agile-projects/