In my area it is very beneficial to use lots and lots of mulch. It saves water and keeps the weeds down, earthworms love it, etc.
Wood chips are good, but I prefer the free ground green stuff from the dump - it decomposes and enriches the soil faster, though it doesn't last as long. Tree trimmers will give their wood chips away for free - it saves them a dump run. They can be found in the yellow pages. Our city gives their mulch away for free also. Locally, you can pick it up in your own vehicle at the dump, or call for a large dump truck full with only a charge for the delivery itself.