Chipping is when you are near the green and want to get your ball onto the green and get it rolling quickly. Most pro golfers have their favorite club anywhere from a 5 iron to a wedge. The main reason is you want your ball to roll as similar to a putt as possible as it hits the green and heads to the hole.
The first thing you must do is decide where you want the ball to hit on the green if you can, as long as you can get it to land on the green. The green is normally flat so when you chip that first bounce is very important and possibly more predictable. You do not want your chip to land on any portion of the sloping green, on uneven areas or in the rough, or you will find yourself in more trouble.
Chipping is truly all in your mind as you try to envision the way you hit the ball, where it will land on the green. Then just do your best to do what you envision.
The club you choose of course is also very important. According to how close to the hole your ball has landed the closer you are you will want your ball to loft, so a sand wedge would be a good choice. On the other hand, if your ball is quite away from the hole you will want a club that has a straighter face.
Of course, you will need practice if you ever want to get good at chipping. Your ball could land in high grass so you will need more loft along with a longer swing. Then there is the time where your ball has found itself in a depression or down low, and once again you will need to figure out the best posture and how high to loft the ball in order to get a good position on the green. Learning which club does the best in different types of terrains is the best way to learn how to chip.