In regards to connections, you will want to use an RCA cable from the "SUBWOOFER OUTPUT" jack on the back of the receiver to the line-level input(s) on the sub. If the sub manual said to use the right input, then that's the way to go. Sounds like you've done all of that correctly.
To get bass to come from the sub, you need to set up the receiver to do that. The speaker set-up menu is explained starting on page 63 of the owner's manual. With your Beta 20 bookshelves, I recommend that you set those to "SMALL", and do that with your center channel, too. With that setting, the bass frequencies from those speakers will be sent to the sub (once you set the "LFE/BASS OUT" setting to "SWFR").
If you're already done that and still aren't getting sound from the sub, please let us know.
EDIT: We can also help you fine tune things, such as setting the crossover frequency (on the receiver and on the sub), as well as the volume level for the sub. Let us know if you'd like us to do that.