Bag them up in black bin bags give them a water and puncture some holes into the bag, tie up. 12 months time you have composted soil that you can put on boarders or use for potting up plants.
You could leave them all over the lawn (an approach I adopt because I`m too lazy to collect them up). You could pile them at the end of the garden and see how many rats nests you can count. I think it is best to dispose of them at your local recycling centre.
I would usually collect the leaves and store them in black plastic bags as honky-tonk suggests or a bin of some sort as in compost. They say you are always no more than 10 feet away from a rat anyway so 237SJ's laissez faire idea is ok too. One last thought I heard on the local radio the other day that RHS Rosemoor are experimenting with leaves as a mulch for their flower beds. Whatever suits you so long as you dont waste them they are a soil conditioner especially if your garden tends to be clay soil.
As you do not know what to do with them .. I assume you know little about gardening. If you want grass next year, rake them up and stick in the green/brown bin.
Don't get rid of them. They will form a valuable soil conditioner once they've rotted down. Put them in a black plastic bag, pour water on them to let them get really wet then jab a few holes in the bag so the moisture can drain away. In time they will rot down to make valuable leaf mould.