TFS often comes with a steep learning curve for project managers, CIO(s), CTO(s) and others in business and IT management. This is unnecessary if approached correctly. One word describes the key in overcoming this barrier. It's SharePoint.
Show TFS and VSTS to developers, DBA(s) and other techies and you'll see them get excited and see the magic of having a one-stop place to do all their work in Visual Studio. Show VSTS to project managers and you'll often see blank stares and confusion as they imagine that this new tool is only going to give them more headaches and work to do. The facts are that TFS was designed with the intent of making life easier for the IT technical workers, especially those who have worked with Visual Studio. Its much like why Boeing and Airbus design cockpits with the needs of airplane pilots in mind rather than the realtime needs of their management back in the office building. During airplane takeoffs, landings and emergency crash landings the last thing a pilot needs is to be called out of the cockpit to file some status report that some office building manager deems as necessary to help them do their job. Well that's how techies often feel about their management. And that's why nearly all project teams and IT organizations struggle with communication.
In my opinion the best way to get Project Managers up/running with TFS is to not tell them they're using TFS. Approach it as a SharePoint site deployment. Setup your Process Template to include the libraries in SharePoint they need to get the starting Project/Excel files they'll need to do their job, the Word templates for documentation/processes, process guidance, reports and organizational links. Get them very familiar with SharePoint.
Once they know SharePoint well enough to be productive then show them how to use some of the tools they'll need to access TFS work items. Start with MS Excel by launching some of the Excel files in the SharePoint libraries that come out of the box in a Team Project site. Train them on how to use Excel with TFS work items. Then show them MS Project with TFS work items. Then show them the reports they can get. Finally introduce them to TSWA, Team Explorer and other tools that can help them see how work items integrate with version control files and builds.