The small blind is always 1/2 the value of the big blind and the blind amounts are set by the table stakes. The minimum bet has to be equal to the value of the big blind. The rest of the players are not forced in any way to put money into the pot unless they want to. When a new hand begins, the dealer button will go to the next person at the table, and that in turn means the blinks will circle around the table as well. Every player at the table will eventually be the dealer, the small blind and the big blind. Every player at the table receives two face down cards from the dealer, starting with the playing who is the small blind. The "dealer" gets the last dealt cards and after that is finished, the first round of betting begins.
The player who left of the big blind is the first one to decide if they will bet, check, or fold. Every player after that can check (if the guy left of the big blind checked), call (if the guy left of the big blind bet), or fold and get out of the hand. The betting continues around the table from player to player until it reaches the big blind who has two options. They can "check" which means they are going to "stay pat" and see the flop OR they can raise the pot with another bet and then everyone else around the table would have to either call the raise or fold. If a raise has happened before the big blind acts, the big blind can call that raise, fold, or re-raise.
The betting continues until the bet is called by all the players at the table or everyone folds to the person who made the raise. If a raise is made and everyone folds, the hand ends and then a new hand is started. Once pre-flop action has finished, the dealer will put three cards onto the table, face up, for everyone to see in the middle of the table.
This is called the "flop" and these cards are known as community cards and can be used by all the players at the table. Another betting around occurs with the small blind acting first. They can check or bet, and all action that occurs after is subject to what was done by the first player to act.
When the flop betting has concluded, another card is dealt face up by the dealer in the middle of the table. This is called the "turn" or "third street". There is another betting round and it is exactly like the betting that occurs after the "flop" is dealt. Then the dealer puts out one last card in the middle of the table and this is called the "river" or "4th street". This is where the final round of betting occurs. After the final round of betting, the players use their two cards and the five that are on the table to make the best 5 card poker hand. Sometimes you may have to use the five cards on the board and none from your hand if say you had 22 and the board was AAKKK, you would play the AAKKK as a full house. If there is a draw, the money is split evenly amongst the people who are tied after the betting is concluded.