My Xmms2 Client PlayLists
If you have just installed some tracks into the Library, you will likely want to create some playlists, Right click on the combobox just above the table and you will get the context menu like this one. I have added a function to create playlists from the album names specified in the id3 tags, if you want a convenient way to play your albums go ahead and click on "Create playlists from Album names" and you will get a playlist for each album in your list.
Alternatively you could create an empty playlist using "Add New Playlist" and return to the Library and select tracks to be added to an existing playlist, although you can just as easily select tracks in the Library and add them to a new playlist directly.
The first option in the list will add the current playlist to your "Now Playing" playlist and start playing the tracks from the beginning, you could also select another playlist and "Add this playlist to Now Playing" list after the current tracks without removing the already set playlist.
If you want to re-order your tracks in the "Playlist Manager", simply right click on a header and select whether to sort ascending or descending (A-z or z-A). For finer control of the order simply drag a track to the position you would like it to be and drop it there.