Many stores manufacture child-sized toilets or at least toilet seats. This can help your boy adjust to going to the bathroom rather than being overwhelmed by a bigger toilet. The child will feel secure and want to eventually use the toilet without the seat as a sign of becoming a "big boy."
Setting a training schedule will be effective for young boys because it allows boys to know when it's time to go the bathroom. Some boys will not be able tell when they are ready to go to the bathroom. When a schedule is made, boys become used to regularly using the bathroom.
Teaching young boys to first sit on the toilet rather than stand in front of it can be an effective and simpler way of learning. Once they master sitting on the toilet, they should move on to standing and learning how to pee.
Celebrate when the young boy tries and gets it right. Do not make discouraging comments when they make a mistake. Encouraging young boys to learn how to properly go to the bathroom can make the transition easier.