You can start kids doing some simple chores around the house as young as 3 to 4 which is when some kids want to begin imitating and helping their parents around the house.
You can have then use the vacuum cleaner to help vacuum with and some will have fun doing that.
You can also have them help pickup their toys and put them away and then as they get older as in 7 or 12 have them do more chores such as taking out the trash, mopping the floors etc.
When they get to age 12 they can usually begin using a push lawn mower and help mow the lawn.
Just start having the kid do chores that are appropriate to their age.