Different people have different feelings about how to use a metronome.
I personally don't like the bell when I'm using a metronome, and always turn it off. I think its usefulness is limited, since I don't think that the best use of a metronome is to teach you how to count measures.
Metronomes are best used to make sure that your tempo in a piece is consistent, not speeding it up in some places and slowing it down in others. This is especially useful when slow practicing to learn a piece; it's very easy to speed up easier parts and slow down harder parts as you are learning, and these changes can be hard to unlearn as you speed up your work.
The metronome tick should also be seen as a fairly rough guideline. Music naturally speeds up and slows down, has pauses, and so on, for dramatic effect. Too strict adherence to the metronome makes the music dull: if a critic calls your music "metronomic" it isn't a compliment!