Don't give away any clues!
The amount you bet can give clues to other players about what hand you have. A new player tend to always bet little on a bad hand and bet much on a good hand. A more experienced player instead tries to confuse his opponents with his betting, and for example make a small betting with a strong hand a large bet on a bad hand. However, the best strategy is usually to give as little information about your bets as possible. You do that by standardize your bets.
A raise pre-flop
A raise pre-flop, if you are first to act, usually means a betting of 3xBig Blind. For example, if the Big Blind is 20, you raise with 40, which make a total bet of 60. Often you add the Big Blind for every player that has called before you act. So if two persons have called the BB for 20, you bet 100 instead of 60. If you are consequent with this, your opponents will not be able to form an opinion of what hand you have, other than that you have a hand which you consider is good enough to raise with.
After the flop
After the flop you usually don’t follow the same pattern. In other words, you don’t bet 3 times the pot every time you bet because that would be to much consider the value of the pot. However, you usually bet amounts relative to the pot size. If there is 200 in the pot and you have the highest pair with a good kicker and want to prevent someone with a flush draw to call you, it is normal to bet the same amount as the pot, in this case a bet of 200. The three most common bets after the flop is 0.5x the pot, 1x the pot or 2x the pot, depending on what you want to achieve.
If you for example have the highest two-pair when the pot size is large and there is two suited cards on the flop, you probably don’t want any other player to get the chance to hit flush. Then you should make a large bet 2x the pot size.
When you bet this much, you have told the other players certain information about your hand. The most common, after the flop bet in NL (aside from all-in) is to bet the amount that is in the pot, called a potbet.

Late position - an advantage
Positions is one of the most basic concepts in poker. If you are in late position you have an advantage because you have information about the other players hands that you wouldn't have had if you where in an early position. You can base your move on what the other players did before you. For example, if a player makes a big raise in very early position it might indicate that he has a very good starting hand.
Pre-flop Strategy
Below is a chart of reccomended starting hands and how to play pre-flop. If you learn this chart well you have a great chance to start winnning money playing poker. This chart is from Howard Lederer's pre-flop strategy. I reccomend you to print this chart first time you play with it.
AA
KK
AKs |
A |
77
KQs
66
ATs
55
AJ |
D |
QQ
AK
JJ
TT
|
B |
AQs
99
AQ
88
AJs |
C |
KQ
44
KJs
33
22
AT
QJs |
E |
s = both cards are same suit
| |
Early Position |
Middle Position |
Late Position |
| Raise |
A, B or C |
A, B, C or D |
A, B, C, D or E |
| Call re-raise |
B |
B |
(JJ, TT) or C |
| Raise re-raise |
A |
A+(QQ, AK) |
A+(QQ, AK) |
After a player has raised to your right, re-raise with group A or B hands. After a player has raised, you should fold all hands not in group A or B, unless you are in the blinds.
In the blinds:
| |
vs. Early Raise |
vs. Middle Raise |
vs. Late Raise |
| Raise |
A |
A or B |
A, B or C |
| Call |
B or C |
C or D |
D or E |
|