If you are looking for the full listing of shows on Treet.TV use the Shows menu in the top menu bar. Following a link from the drop down list will take you to the Show page, where all episodes can be accessed.
If you know the name of the show or episode you can also use the search tool in the top menu bar.
The topic cloud in the right hand column is also a good way to find shows according to subject matter.
Live shows can be seen by clicking on the Watch Now button in the top right hand corner.