Codeplex gave me the relevant information for proper connection, and I connected to my repository using the Team > Connect to Team Foundation Sever in VS 2010 Ultimate.
Here is what I see:
How can I push the code I have made on my machine, to the repository on CodePlex?
The easiest way to get started is to right click on your solution in the Solution Explorer tool window and select the "Add Solution to Source Control" command. Then, open the "Pending Changes" tool window from the main Visual Studio menu by selection View, Other Windows, Pending Changes. Lastly, click "Check-in" to check-in your files.