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.
Snowballing is when one person passes on the cum from their mouth to another, increasing the spit and the 'snowball' effect. For some of the swappers (particularly those who choose to be sexually submissive) this can be a particularly erotic activity to take part in - and the other side of the equation gets to enjoy the sight of their partners loving being covered in their semen. Some people also enjoy participating in the swapping of their own ejaculate, which can be a fun thing to experiment with if the idea appeals to you!
By and large, the people on the recieving end of a blow job prefer their partner to swallow their semen. This isn't a universal truth, of course - pretty much nothing is! But it's a solid rule of thumb in almost all cases. Plenty of blow-job-givers love the act of swallowing as much as the other side of the equation enjoys watching it, and for some - particularly submissives in BDSM-style relationships it can be a fantasy and a huge turn-on.
If your partner doesn't like the idea, though, you mustn't press the issue, there are loads of valid reasons not to want to swallow someone's ejaculate, and just not feeling into it is absolutely one of them! It's possible to learn how to enjoy it if it's something they'd like to be able to do, but there's absolutely no reason anybody should feel obliged to try if they're just not into it.