I waited to post this until the leaves were finished changing colors here and mostly on the ground. In the interim, I have seen others posting about some of the same ideas. (see bottom)
Most of us rake up our leaves. Some of us bag them, some can dump them on the roadside and let the town pick them up. Fewer people mulch them. But you might want to consider letting them stay where they fall.
The leaves that fall and stay there in woods (known as leaf litter) are habitat for salamanders, spiders, centipedes, millipedes, worms, and lots of insects that most of can't identify.
Leaves are important for wildlife and there is a cycle of life contained there. If you raked up under that fallen forest log, you would be destroying some wildlife.
One species you might find there are the butterflies that find shelter (in the egg, pupal, or adult form) as a protected place to over winter and wait for spring.
Besides shelter, leaves offer food to some invertebrates who in turn help break down the leaves, which feeds the soil.
Deeper piles support spiders but ladybugs, salamanders, toads, and other predators of pest insects (like aphids) are fine with naturally occurring piles.
Of course, I understand if you don't want piles on your front lawn, but consider leaving a pile or two in the backyard corner. When spring comes, you can watch the birds picking through the leaves in search of a natural meal.
And more people are trying out leaving the leaves, using them as mulch or running a mulching mower over them and letting the leaves help the lawn's soil. (Not as easy with all the oak leaves that I have in my backyard. Their size and chemicals make them slower to break down than most other deciduous tree leaves. They might form a mat that could actually rot your plants underneath.)
Even if you rake your leaves or don't have leaves to clean up, there is a good lesson here for kids. I found one lesson on the National Wildlife Foundation blog. Some leaf litter exploration is a great little nature lesson (even for adults).
Some books for young readers include Look What I Did with a Leaf!
and Why Do Leaves Change Color?
And don't forget The Lorax by Dr. Seuss. I wrote a post about that book recently elsewhere but it's a good environmental stewardship tale for all of us.
Others writing about leaves, raking (or not raking), and leafy wildlife includes these: