The apparent rules of blackjack are simple : collect cards that amount to but do not ecceed 21. However, as any card sharp will tell you, there is alot more to it than that.
First, when you walk up to a blackjack table, observe whether people are actually winning. Casinos often rig tables or decks so that player's winnings are disproportionately low to the bet being laid. There is no piont in playing a rigged game where you know you will lose.
Next thing to understand is that contrary to popular belief, the object of the game is not to score 21, as may would tell you, but to beat the dealer. It makes little difference if you have 13 and the dealer has 14. He beats you anyway even if no one has 21. Of course, the actual game is a bit more complicated, since you almost never singly against the dealer, but also against other players as well.
Now, the most important rule of blackjack is to enjoy yourself. Now, this may seem like an obvious thing, but many people forget to have fun where money is concerned. The minute fear overtakes you, you are then in the casino's hands and they will not let you escape until they have all you money.