A: Many men experience ejaculating before they and their partner are ready. There are several steps to mastering and consistently being able to delay ejaculation. The first step is to strengthen the PC or pubococcygeal muscles. This muscle is easy to identify because it stops the flow of urine when you squeeze it during urination. By pulsing and releasing this muscle twenty times in a row and relaxing the pelvic muscles in-between, you strengthen the PC muscle. (By the way, women benefit from a toned PC muscle as well. A toned PC muscle strengthens orgasmic sensations.)
Next, you will want to learn how to bring yourself to the edge during sex play. Stimulate yourself almost to the "point of no return" and then relax, breath deeply and allow your arousal state to lessen. Then begin to stimulate yourself again. You can practice this as many times as you like until you can easily come to the edge and not ejaculate.
There are manual techniques that you can use as well: squeezing the head of the penis and firmly pressing the area between the scrotum and anus are two. There are visualizations that you can practice that support you in learning to master the art of delay.