Fingering is a common term for what is more properly called 'digital stimulation'. Neither phrase sounds particularly sexy, but for a lot of people the reality is red hot: many people with clitorises find that they can't easily reach climax without a little attention in this department.
The key to great fingering is better communication. Ask your partner what they want and what they enjoy; you could try asking them to use your hand as though they were doing it themselves to help you learn what it is that they like.
If you're on the other end of the equation and you aren't sure what to ask for, experiment! Masturbation is a natural, healthy way to get in better touch with your own body - and there's no better method of finding out what turns you on.