How do I download a song I like ?

Depending on which page you are for the song you like, you should be able to find a link called: Download or Downloads.

Single click on that link. Assuming you have JavaScript enabled, you should get a popover window with a listing of one or more downloadable files. Right click on the first file on the list and initiate the download (the exact menu item after the right click depends on the browser you’re using).