If you are looking at the iPod's Music settings screen in iTunes (where you set it to Sync Music), I don't know why the new album does not appear under Albums. As an alternative, create a new playlist in your iTunes library. Add all songs from that album to that playlist. On the iPod's Music settings screen in iTunes, under Playlists, find that playlist and select it. Click Apply.
I sync my iPods using playlists, instead of selecting albums or artists. I can update content on my iPod by simply updating the playlists (add/remove songs) that sync to the iPod. The iPod does not need to be connected when I make changes to those playlists. I don't need to go to the iPod's Music settings screen each time I want to make changes to the iPod's content. I just connect my iPod, and iTunes automatically syncs the same changes (that I made to those playlists) to the iPod.