Are you a poker newbie? You can find a few helpful tips to get you started in the poker world here. Stick to them and you'll find yourself under poker's spell.
Don't play every hand. You have to learn to fold if you have bad cards.
Don't bluff straight away; your opponents will know.
Pay attention to how many chips your opponents have left. Don't go for a pot when your opponents still have more chips left. They can just outbid you.
Don't act rashly. Before you start betting, make sure that you observe your opponent's behavior. However don't leave it too long; you must act within a certain time frame.
Make the most of your position at the table. The later you go in a round, the better you can react to what your opponents do. Don't play every hand when you're in one of the earlier positions.
In this situation you can however react to a bluff. If there have not been many bets in a round then most of the players just stay in to get the blind. You can counter such a bluff by making a raise with a large amount (Squeeze play).
Assess your pocket cards realistically. Just because you have a high card, such as an ace, this doesn't automatically mean that you have a good hand. You have to have a good combination with both hidden cards.
Take the opportunity in no limit games to go all-in! If you have a really good hand, you should take the risk. Avoid playing all your chips as a bluff too often. Your opponents will see right through you!