Let the child help by placing the stamps so the child will be part of the process, but what's important is that the child sees how a necessary task is approached and carried out. There is no question that parents should not do the child's homework nor assume responsibility for getting it done. Parents must provide the homework environment. Children don't have the wherewithal to buy a desk or a dictionary. That's your job.
Every child needs a quiet place to work with no other people or distractions around.
Ideally this is the child's own room. If the room is shared with a younger sibling, parents need to find a creative solution which will give the school child the proper environment for work without interruption. Every child needs the necessary equipment for homework just as you need necessities at your desk at work. To start, the child needs a desk or table with good lighting, an age-appropriate dictionary, paper, pencils, etc. Later parents may need to add a calculator or even a computer.