Streams / Stations
Radio stations are listed in the right pane. Usually they have a title and a description. The description is often the last played song. (This isn't updated automatically to conserve bandwidth and because live information is seldomly available.)
You can double click a station line to get it to play. Alternatively there are the play and record buttons in the menubar. You can also invoke a stations homepage, if it has one.
Actions
Context menu
Additionally most actions are available in a context menu. Right click a station entry to display it.
You can always click the current category in the left list, to have the current station list redisplayed. Which is useful after updating favicons, or accidental dragging of entries.