Ever since I noticed my neighbours putting their leaves in the garbage a few years ago, I have been "rescuing" other people's bags of leaves. Why? Because I only have one decent-sized deciduous tree on my property (but many, many spruce) and I don't have nearly enough leaves as I (or the kids) would like.
So I rescue other people's bags and first dump them on the back lawn for the kids to jump in for a while. When they've tired themselves out, I mow the pile a few times with my push mower to chop up the leaves, then I start dumping them in the gardens for mulch. Technically you should wait until the ground has frozen to put winter mulch down, but when you're a busy gardener who works full-time and has kids, you do things whenever you have the chance even if the timing isn't optimal!
I've written about the benefit of leaves before - they are high in nitrogen and they insulate the soil from our wild temperature swings and drying winds in wintertime. This past spring I didn't even bother to clean them up! You are supposed to remove winter mulch in order to help the soil warm up faster in the spring. Again, here I don't follow the rules and maybe my garden is a week or two behind in the spring, but minimizing work is a higher priority for me! Dried leaves don't look as pretty as fresh, clean soil does but you can put some compost on top of them in the late spring for a cleaner look.
I even save and reuse the garbage bags from the bags of leaves that I rescue! I'm sure the neighbours think I'm crazy, prowling the back alleys and lurking around the leap drop-off area, but I really think I'm doing the world a favour!