There's a clearly defined line between helping your child complete his homework on his own, and doing it for him. However, some parents seem to have no qualms crossing that line. They willingly do their child's homework, prepare projects for them, and generally shoulder as much responsibility as they possibly can to ensure that their child makes the grade. Although you may have your child's best interests at heart, this is definitely not the best approach to take, as it will only teach your child to grow more dependent on others instead of relying on himself to complete a task.
Here's how you can help your child with his homework, without doing it for him.
When your child receives homework, help him by planning out how he will fit it into his busy schedule. Often, children receive homework during their vacations, and most of them will pull all nighters trying to complete two month's work in two days at the last minute. Instead, help your child plan how and when he plans to complete his homework. Let him select how much time he will allot to his assignments and help him work out a schedule. If necessary, let him write it down. With a little encouragement from your end, your child will then stick to the schedule, especially if he has planned it himself. This will teach him how he can manage his time better - a lesson sure to come in handy later on in life.
Your child needs to take responsibility for his actions if you want him to grow up into a responsible person. Instead of constantly pushing your child to complete his assignments, remind him, let him know you're there if he needs you, and leave it up to him. If he still doesn't do his homework, let him suffer the consequences a few times. Chances are, he will be more careful in the future.
Show an interest in what homework he receives from school everyday. Different children get motivated in different ways. Some children are entirely self-motivated and parents may need to tell him to stop studying and take a break, while others shy away from studies and no amount of parental pressure can get them to pick up their books. However, on a average, if your child knows that you are involved with his studies, he will tend to take your advice a little more seriously than if you have no idea what's going on at school, but just keep yelling at him to finish his homework.
Children often want to be where the action is. If you are in another room with the others while your child has to go alone and sit in his room and finish his homework, it may be a deterrent. If you see that your child is reluctant to go to his room, see if your sitting there and reading a book while your child does his work, helps. Alternatively, let him sit on the dining table and complete his homework, if he finds that comfortable.
Although you shouldn't do your child's homework for him, you should let your child know that you are available to clear any doubts he may have, no matter how busy you may be.