To submit a changeset in Visual Studio you must have 'Submit from SCC on Checkin' enabled in your options menu. This is described in the section called “SCC”.
There are two ways to submit a change. You can either select a checked out file and select 'Check in' or you can use the Pending Checkins tab to control which files are selected in the Submit Dialog. The 'Pending Checkins' tab also allows you to see which files have been checked out inside this Visual Studio project/solution.
By using the Comment section you can set the description for the changeset you are going to submit. To submit these changes you check the files that you want to submit to the server and press the Check In button.
This will launch the Changeset Dialog as described in the section called “Submitting a Changeset to the Server”. Any files selected in the pending checkouts tab will also be selected in the Changeset Dialog.
When you are happy with the changeset you press the 'Submit' button.