Poker Blinds

Dealer Button - The Button moves from player to player at the beginning of each hand and identifies the current dealer position. The player at this location is considered to be the dealer. After each hand is completed the dealer button is moved to the next player to the left.

Blinds - In Texas Hold'em, there's no ante, so the two players to the left of the dealer must post blind bets. A Blind is a forced bet before you receive your initial cards and is posted by the players to the immediate left of the dealer button. This is used to seed the pot with cash. Everyone at the table takes their turn playing the blinds. No one is immune.

Small Blind - In our Hold'em game, the small blind is equal to one half the minimum bet rounded down to the nearest dollar. (Ex. $5/$10 game, small blind = $2.00)

Big Blind - In our Hold'em game, the big blind is a bet equal to the minimum bet. (i.e. $5/$10 game, big blind = $5.00)
When you first take a seat at an active table you're required to post the equivalent of the big blind. You can do this by waiting until you are in a position to post it. Another way would be to post it out of position. If you decide to post out of the big blind position, you must also post the blind when you are in position if you wish to remain in the game.
If you were to miss the regular rotation of posting the blinds, you will be required to post the big blind in order to re-enter the game. If you were to sit out and miss three big blinds, you would then be removed from the table, forfeiting your seat.