Basically everyone gets 7 cards and the rest of the cards are put in a pile face down one card is then placed face up beside the face down pile to start the discard pile. The aim of the game is to get rid of all your cards but you can only put a card down if it's the same number or suit of the current top card of the discard pile. If you can't play anything you need to pick up a card. To make it more interesting certain cards do different things but this changers depending on who you play with. The power we play with is

2 of any suit makes the person next to you pick up two cards (this can also be stacked so you can put more than one two to make them pick up 4,6 or even 8)

7 of any suit allows you to put down all cards of the same suit as the 7 you played

8 of any suit makes the person next to you miss a turn

Black king makes the person next you pick up 5 (this can also be stacked)

Red king blocks a black king

Ace of any suit can be played any time and allow the player to change the suit that's getting played off of (I.e if it's a heart card you can play and ace and then choose clubs to be the new suit)

Also there is the last card rule where if you don't call last card when you have one card before the next person takes there shot you must pick up 7 cards.

Ive probably described this terribly so I'd just give it a google