The first thing you need to know about cricket is that it is played between two sides, of 11 players each. The length of the game can vary from lasting for several days, to being over within a few hours. Those types that last for more than one day include Test match cricket, which lasts for 5 days, County Championship games, which last for 4 days, and minor county games, which last for 3 days. Games which last for just the one day include formats which are either 60 overs per side, 50, 45, 40 or at its shortest form, 20. An over consists of 6 legal balls. To bowl a ball, the bowler has to run up and bowl the ball overarm, he is not allowed to throw the ball, the action is more that of a windmill. The ball, whilst it doesn't have to bounce has to reach the batsmen below waist height (if it is a seam bowler, a spin bowler it has to be below shoulder height as they are generally slower bowlers). A non legal ball will be called either a wide or a no-ball by the umpire (who is crickets version of a referee, there are two of these in amateur cricket and 3 in professional). A wide is a ball which is deemed by the umpire to be two wide of the batsmen in his normal stance to hit. A no-ball where the ball either bounces more than twice before reaching the batsmen, is too high when it reaches him and hasn't bounced, the bowler has been deemed to throw the ball, or has overstepped the mark and has bowled from two close to the batsmen.
All of this takes place on the pitch. This is a 22 yard long strip of short, rolled grass which is as flat and hard as possible. It is 10 feet wide. At either end of the pitch, there are three upright stumps, with two bails laying across the top of them (all together these for the wickets, each stump has its own name as well, the leg stump is the stump which is closest to the heel of the batsmen, the middle stump is, of course the middle of the three stumps, and the off stump is the stump furthest away from the heel of the batsmen). The batsmen will try to stop the ball from hitting these stumps, otherwise he is out. There are several ways that a batsmen can be out, all of which will be explained later. Also on the pitch there are two lines called creases, these dictate how far forward the bowlers front foot can be before he is deemed too close to the batsmen and a no-ball is called (his front foot must be completely over the line before it is called a no-ball). The batsmen will try to get as many points (called runs) as possible before they are out. There are always two batsmen and once 10 batsmen have been out, the sides swap over and the batting side bowls, and vice versa. In games that last more than one day, each side will bat twice, unless the game is won before or weather intervenes. For a batsmen to score a run, they have to successfully cross and get to the opposite crease before the fielders throw the ball in and the bails are knocked off by it. Batsmen can run more than once if they wish. If the batsmen does not hit the ball, yet they complete a run, it is called a bye. If it hits their body, and they have tried to hit the ball it is called a leg-bye. A batsmen can score without physically running as well, if they hit the ball and it travels over the boundary (the outside line of the ground which runs generally about 60-80 yards away from the pitch in a rough oval shape) without bouncing, then they score 6 runs, if it bounces, they score four. They do not get any extra runs by running between the wickets. You can score 4 or 6 byes/leg byes.