The most important thing to consider when you start playing poker is that not all start hands are worth bothering. If there is little prospect of profit, it is advisable to fold. You should always prevent yourself from losing money in games were you never really stood a chance. Novice players often have the tendency to play as many hands as they can. This might work with other card games, but with poker your goal should always be to end the evening with more money than you came with. Try to be selective. Find out which combinations are possible with your start hand. Folding is sometimes the best decision to make, even later on in the game.
For experienced players, bluffing can be an excellent way of forcing opponents to give in and winning the pot in spite of their bad start hands. However, rookie players should always be very careful. Much of it is depending on the style of your opponents, the cards in their hands and of course your own attitude.
Timing is really important in bluffing. Bluffing too often in silly situation might cost you your credibility.