Several times I found myself wanting to try out different features of TFS 2010, but my only options appeared to be building a virtual machine (time consuming and requires gobs of money or an MSDN/TechNet subscription) or using a live server as a guinea pig (for some reason admins frown on this). Luckily there's an easier option, I just wasn't aware of it until last week.
Microsoft has virtual machine images for a full TFS 2010 server installation, along with sample labs if you're just getting started with TFS.
- Visual Studio 2010 RTM (Hyper-V)
- Visual Studio 2010 RTM (Windows  Virtual PC)
- Visual Studio 2010 RTM (Virtual PC 2007 SP1)
Brian Keller posted more information on the images and what they have included as well as some information to simplify downloading the collection of .rar's that compose each image.
Besides trying out the built-in tools, I also intend on playing with some of the additional templates that are out there for project and task management in TFS.
As if that isn't enough, there is a remarkable amount of information at MSDN on the test labs, Build process, Branching, Requirements Management, Integration, ... the list goes on.