Online poker is one of the biggest successes in internet casinos. We look at how online gamblers unfamiliar with the game can get started.

As the enormously successful flotation of PartyGaming shows, online poker is simply huge. With televised games, Hollywood celebrities getting to grips with green felt, and high-profile tournaments, poker has never been more fashionable, and it's not surprising that many online punters who usually prefer roulette or blackjack would like to give it a try.

Online casinos are a great place to get started, because unlike land-based casinos, they offer a wealth of opportunities to practice. Most online poker rooms, such as William Hill Poker Room, offer free games where you can brush up on your new skills, as well as tutorials and plenty of information about the rules, all of which you can study at your leisure before you begin.

There are several types of poker available to play online. All these variations have different rules. However, the most popular, and the easiest to learn, is Texas Hold 'Em.

The aim of the game...

...is to build the best five-card hand from the cards available. Betting patterns vary depending on what limits are set and the type of game. Texas Hold 'Em kicks off with the posting of the blinds - the compulsory bets that get the game going. A big and small blind are posted, with the big blind being 2x the small blind. These are usually posted by the players to the left of the dealer. Everyone takes it in turns to be dealer.

Once the blinds are posted, two cards are dealt face down to each player. These are the pocket or hole cards. A round of betting follows.

Three community cards, which players can use to build their hands, are then placed face up in the centre of the table. This is called the flop. A round of betting follows.

The dealer then puts the fourth community card in the centre of the table. This is called the turn. A round of betting follows.

A fifth card is then placed by the dealer in the centre of the table. The players then know their best five-card hand from the seven cards available and a final round of betting follows.

The end of the game is the showdown. All players must show their hands or concede defeat without revealing their cards. The winner is the player with the best hand.

Hands are ranked as follows:

1. Straight flush

A straight of one suit, for example: Q, J, 10, 9, 8 of diamonds. A royal flush is an Ace high straight of one suit, for example: A, K, Q, J, 10 of hearts.

2. Four of a kind

A hand with four cards of the same rank, for example: four fours.

3. Full house

Three of a kind plus a pair, for example: three eights and two sixes.

4. Flush

Five cards of the same suit.

5. Straight

Five cards in sequence.

6. Three of a kind

Three cards of the same rank.

7. Two pair

Two cards of one rank plus two of another rank, for example: two eights and two fives.

8. One pair

Two cards of the same rank, for example, two threes.

9. High card/no pair

When you have none of the above, your hand is determined by your highest card.