Yes Home Depot rents fantastic Rototillers. The rental models are high power and high quality models which are normally too expensive for the average homeowner to purchase. Home Depot will also instruct you on how to use the Tiller.
The Home Depot in my town does not have Rototillers but the local rental shop (Rental Depot) does. So I would check if you have other rental options. I'd check the yellow pages. I'm unsure of the price they rent for but most of them are a 4 hour minimum.
The Home Depot does rent tillers as well as many other tools. It is best to call your local store for price and availability as it may vary from store to store.
You should be able to rent a rototiller from most rent places. Sometimes you can find a good used one for a cheap price. Rent places have a variety of various equipment.
There's sort of a drainage issue along the north fence in our back yard, so we needed to widen the flower beds, till up the ground, and plant something in there that can stand living in a bog. To that end, we needed to rent a rototiller, which we got from Home Depot.