Which files we have to add to Source control (TFS)?

Hi There,
Curently i am working on MVC Project using VS2012. I have created the project in local and have to add to the source control.
do we have to add all the files and folders? like dll's ,packages folder.
Can you please let me know which files we have to add it to source control and which to not.

Thanks in advance.

Thanks and Regards, Gangadhar.