Poker is a card game in which players form a hand based on the cards they have. The highest ranking hand wins the pot at the end of each betting round.
To play poker you must first ante up some amount (the amount varies by game, for our games it is typically a nickel). Once everyone has antes, players are dealt a hand of 5 cards. When it is your turn to act, you can either call, raise, or fold. If you call, you must put the same amount into the pot as your opponent. If you raise, you can increase the amount that you put into the pot. You can also exercise pot control by calling to keep the size of the pot manageable.
One of the biggest mistakes that beginner poker players make is not knowing when to fold. This is because many players assume that they are going to win every hand, and so they continue to play them even when they should have folded. The divide between break-even beginner players and those who regularly make money is often not as large as you might think, and it usually has to do with changing your mindset to view the game in a cold, mathematical, and logical way.
Another important tip is to always try and guess what other players have in their hands. This can be done fairly easily, and it will pay off in the long run if you do it. For example, if someone calls a bet after seeing a flop that is A-2-6, you can conclude that they probably have a 2.