I had great experiences gathering up leaves from the fall and using them on beds.
I let the leaves overwinter on my raised beds. In the spring, I poked around casually, and found worms galore partying just beneath the surface.
A bit later in spring, in about April, I noticed lots and lots of spiders making families.
I planted directly in the leaves. I dug little nooks for my plants and dropped them right in, then put leaf cover back around them. The herbs and vegetables that I placed in that environment have grown great. I have not watered any of the leaf-mulched plants at all.
It's starting to become summer and I have noticed mosquitoes and gnats in the leaves, and some ant colonies sprung up near my house in the leaves (the ants started coming into the house, which I didn't like.)
All in all I heartily recommend this method. I do advise a mix of different leaf types, and not to use a big majority of oak leaves (I think my neighbor has a giant oak), as I noticed oak leaves take a long time to break down.