How you play a poker tournament

There are many different types of poker tournaments. These are some basic tournament structure guidelines.

All participants enter the tournament for the same cost (if it's not a free roll). This is known as the buy-in.
The casino or poker room takes out an entry fee from all participating players (if it's not a free roll). If the buy-in is $60 the entry fee might be $6, making the total amount paid by the players in the tournament $66.
In this case, if there are 100 players in the tournament, the total prize pool will be 100 x $60 = $6,000. The casino or poker room will take out a total sum of $600 in entry fees. That's how they profit from hosting tournaments.
All participants will have the same number of chips at the beginning of the tournament. $1,000 or $1,500 are examples of common starting amounts.
In a tournament with 100 participating players there will normally be ten tables with ten players each at the start.
As the tournament progresses, the stakes (antes and/or blinds) are generally raised in 15-60 minute intervals.
When a player loses all his chips he will be eliminated from the tournament (if it's not a re-buy tournament. In those a player has the chance of buying in again during a specified time period).
As players get knocked out of the tournament, the tables are broken-up and re-configured and other participants are moved around. For instance, if there are ten players at one table and seven players on two others, two players from the ten-handed table might move to the seven-handed tables. This will result in three eight-handed tables.
The tournament is over when one player has eliminated all his opponents and has all the chips. This lucky player will receive the first prize. In this example it would be 30% of $5,000 = $1,500.
A common prize structure is to have a prize for about every ten players in the tournament. In this case (with 100 players), it might be 30% for first place followed by 20%, 13%, 10%, 7%, 6%, 5%, 4%, 3%, and 2% respectively. Ten prizes in total.