The way "gambling skill" works in GURPS, for example, is that it allows the character to recognize what the odds are, know how someone might be cheating (maybe to spot that), know what the rules of a game are, and so forth. Over the short term in any sort of gambling, though, it's largely about luck. Being a really good poker player doesn't get you better cards, it just helps you recognize when to hold them and, conversely, when to fold them. Averaged out over a whole evening of playing, though, it's really a lot like a contest of skills. The good player has a substantial advantage over the inexperienced player.
You *could* play an actual hand of poker, or whatever game, but you said you don't know any of them, (and I figure if you want to play poker with your friends, you should just do that, instead of having your characters pretend to play poker).
So here's my idea for it:
Make the whole game (one evening of poker, for example) a sort of Extended Test with an interval of an hour, or half hour, ten minutes, or whatever you like. The value of a hit (in nuyen) is either what everyone agrees on or what The House says it is (and if you don't like it, don't play). The threshold determined by everyone agreeing on a number (or the house assigns it. The higher this threshold is, the
less chance is involved, by the way). Each participant rolls Intuition + Gambling skill and adds up their hits (alternately, assume that the rules and odds of poker are fairly simple, and use Con skill instead). You can spend Edge on each interval, but it doesn't refresh until it normally does in your game (end of the job, end of the story, Wednesday afternoon at tea-time). Once the threshold is reached by anyone, or if you've hit the time limit (if one guy needs to leave after three hours, for example), the game's done. It doesn't matter if more than one player "wins" this way.
Now, for each hit you get beyond what someone else gets, they owe you the value of a hit. Do this for everyone, and that's the game.
So for example, there's three goons playing Texas Hold'em while waiting for their goon buddies to pick up the guy they kidnapped. The value of a hit is a hundred nuyen. The threshold is 20 (or they decided they have four intervals of time). After four intervals, Anton has 23 hits, Bullit has 20 hits, and Cabron has 17 hits. Game's done. Anton is the big winner, so he doesn't lose any money. Bullit has 3 less than Anton, so he owes Anton 300 nuyen. Cabron's the big loser, owing Anton 600 nuyen (23-17 x 100) and owing Bullit 300. Anton walks away with 900, Bullit breaks even, and Cabron is out 900

.
If someone has to leave early, just tally up the scores, divvy up the money, and then continue with the remaining players until the end is reached.
If you want Edge to factor in more, you could link the Gambling skill (or Con skill) to Edge, or to (Intuition + (Current) Edge), or let the player use the higher attribute. You wouldn't have to spend Edge each interval (although you could, to get extra dice), even though you're "using" it for the skill.
I like (Intuition + Current Edge), because it's sort of like your luck is being used up avoiding tripwires and robot guns and explosions, and then isn't around for you to win at card games.
Add in whatever other things you like, such as the option of a test to count cards, giving you an extra hit or two if you beat the threshold (but subtracting hits if you don't), adding a Composure test at the end of the extended test (add the hits from that to the hits scored already), or allow "cheating" (a secret Palming test, rolled by the GM, and everyone gets a Perception test to beat it. If it's successful, the cheater gets an extra interval, again rolled in secret by the GM. If he's spotted, well, that depends on the situation, and he might just be made to quit or he might have a gun pulled on him).
Hope these ideas help.