For your team
You have many choices in how to deploy TFS, from putting everything on a single server all the way to using multiple application tiers, multiple SQL instances, and a SharePoint farm. See our hardware recommendations for more detailed help in determining the right type of deployment for your team.
A single server deployment is the easiest way to deploy TFS and is a good configuration for small teams not planning to use reporting features.
A dual server deployment, with separate application and data tiers, is a good configuration for medium sized teams and small teams planning to use reporting features.
Larger teams or teams with heavier usage (via automated builds, for example, or via having large amounts of version control data) should consider multiple server deployments, which can involve multiple application tiers, multiple SQL instances, etc.
For evaluation or personal use
If you're setting up TFS for personal use or to evaluate the core features (version control, build and work item tracking), use TFS Express. It's free, it's simple to set up, and it can be installed on both client and server operating systems.
Of course, if you want to evaluate all of the features of TFS, like reporting and SharePoint integration, you should install a free trial of the standard TFS product with those features enabled.
You might also want to consider using a free Visual Studio Team Services account for personal use. Because it's in the cloud, you won't have to install SQL Server and TFS on your own hardware, and you won't need to do things like manage your own backups.