At the begining each player is given a stack of chips to bet with. Each chip has a set vaule as shown in the picture below

Before any cards are delt there are manditory bets added to the pot called "blinds". Blinds are there to entise players into betting to claim the pot.
The 2 players to the left of the dealer start the pot with the "small blind" and "big blind" respectivly and the small blind being half what the big blind is.

The blinds rotate clockwise after every hand and move one player at a time so the big blind would then become the small blind. The blinds also increase after a set time. For example you may start off with the blinds being at £25 and £50. Small blind being £25 and big blind being £50. Then when the blinds go up they would become £50 (small blind) £100 (big blind) then £100 (small blind) and £200 (big blind) then £150 (small blind) and £300 (big blind) ect.

Once the blinds are in 2 cards delt to each player, these are known as "pocket" cards or "hole" cards.

After the pocket cards are delt each player in turn clockwise from the big blind can either fold, call (matching the big blind bet) or raise (matching the big blind and the betting atleast the big blind again). The small blind will need to call the next half of the big blind or meet a raise or fold.

The big blind, if there has been no raises can "check". This means that the player does not have to enter more chips in the pot.

Once the first round of betting is done 3 cards are drawn known as the "flop".

The next round of betting starts with the player direct the dealers left. Again the players can either check, bet or fold. Once this round of betting is finished another card is drawn.

NOTE: If a player rasies and gets called the player who raised can not raise again.

After the last round of betting another card is drawn known as "the turn". Once this comes out another round of betting takes place.

Again starting from the dealers left another round of checking, betting, raising or folding takes place before the final card.

The final card known as "the river" is produced after the last round of betting.

The last round of checking, betting, rasing or folding takes place before the players hands are shown.

Assuming players are still in at this stage and haven't folded, this is where the players show their hands against each other and the best hand takes the pot.

NOTE: If players have the same hands the pot is split.

If during any betting round a player goes "all-in" (bets all their chips) and other players raise to more than the all-in players there is now a "side pot". The side pot is what the player who went all in can only win.