Syrian hamsters are very tolerant of kids, live longer and are solitary in the wild, so they don't need so much attention, but they are nocturnal, so they sleep all day and are most active between about 11pm and 3am. Dwarf hamsters are most active at dawn and dusk, so make more useful pets. Dwarf hamsters are social animals, so they need a lot of attention and will bond with their owner. It's very cruel to keep any hamster in a cage and not give it stimulation as they are inquisitive, bright little animals which love to explore. Don't take a Chinese dwarf hamster as they are too timid to make good pets for children. Russian dwarf hamsters are a far better choice.
I'd say hamsters need a large cage with bars to climb and different levels to explore, shredded paper over the floor and soft tissue or fabric which they can incorporate into a nest. You needn't clean out the whole cage but just the area where the hamster is peeing - what I do is take some of the soiled material and put it into a jar sitting on its side over the area where the hamster pees. The hamster will then start to pee in the jar and you need simply remove it and wash it out daily, plus refresh the water and give fresh food, etc. They love a variety of fresh food - scraps of greens, sweet peppers, little pieces of fruit.. only give tiny amounts they'll eat at the time otherwise they'll store it and it'll go mouldy.
Every week or two you can remove some of the dried droppings from around the cage (I use tweezers) , and take a little portion of the bed away and supply fresh bedding which the hamster will incorporate into the old bedding. Never disturb the hamsters bed too much, as it stresses them out. They're very clean little creatures, and will keep their cage spotless if you support them in the ways I described.
Give them plenty of opportunity to play and explore by putting toys into their cages - ladders, egg boxes with bits cut out for them to go in and out of.. tubes.. It's amazing what you can make with cardboard, scissors and sticky tape for the hamsters to enjoy. it's fun to experiment with ways to encourage them to play and if you encourage your son to do this, it will become an absorbing activity for him and help him to bond with the hamster in a way which is healthy for the hamster.
Although as an adult hamster owner I hand-tame my hamsters and hamster-proofed my home to enable the hamsters to play and explore freely, I'd caution that they are tiny and so any freedom must be carefully supervised by an adult 100% of the time, because there are so many potential hazards for such a tiny, active little creature. You shouldn't allow a hamster out of the cage unless it is hand-tamed, because it'll be very challenging to catch. Mine were all hand-tamed, but I usually just keep the cage on the floor with a ladder leading inside and the hamsters go in themselves when they're ready. A hand-tame hamster will happily climb onto your flat palm if you hold it out to them.. or they'll allow you to lift them gently using a thumb and fingers around their middle to return them to their cage. It's just a matter of patience, gentle handling, respecting their space and needs, and building their trust over time.