Upon an indication that you want to play, the dealer will stack the cards and begin a formalized routine known as the shuffle. Most casinos have a particular shuffle method the dealers are instructed to use to insure that the cards are in a random sequence. This is done to indicate that each shoe presents the cards in a fresh and different order from any previous, to allay any misgivings concerning cheating on either side of the table.
Some casinos employ a mechanical shuffler to cut down the amount of time wasted.
From the casino's point of view, any time when the cards are not in play is valuable time lost. The cards are then placed in the shoe, with the front of the cards usually where the cut card was placed. The shoe usually sits on the table close to the dealer's left hand, with the open end where the cards are ejected facing the players. This card is then removed and placed by the dealer toward the back of the shoe, leaving 1.5 to 3.5 decks remaining. The placement of this card is important as it determines what percentage of the 6 or 8 decks will be played, the general theory being, the more cards are available for play, the greater the potential player advantage.