Recently Microsoft released a new open source project, aimed at all these developers who would rather avoid to use Team Foundation Server but they must do so – for several reasons – instead of using Git.
Then it came out git-tf: a bridge for using Git as a local repostitory, after which every commit can be merged as Team Foundation Server changesets.
After you set a local repository up (git init), I suggest you to copy the git-tf files over there. Then you have to bind the local repository to the Server and the Team Project:
Once you’ve done this, you can start adding/modifying the involved files. As a sample, I added a file into the local repo and I committed the file:
We’re only missing the check-in 
and here we are!
This is the first step toward the Distributed Version Control System from Microsoft It still misses some features, but from version 2.0 (so the latest) on it is a feasible way of letting everybody use what they want inside the company