Gravel? (sorry lame joke)

Location? Climate? Budget? Family? Pets? What type of entertaining? Sports? Trees? Privacy? Neighbours? House? Style? Just to name a few questions.

Create an ideabook, use several different searchwords, for example: http://www.houzz.com/photos/outdoor/%2Blarge-%2Blow-%2Bupkeep-

So, he has a rectangle twice as wide as it is deep. If the house is in the middle, then I'd start by dividing it in thirds and think of each third as a room. If the house is on one half, then there's two rooms. Side yards are additional rooms.
I'd start by deciding where to put seating, barbecue, etc. Next consideration is for shade/shelter. Think of plants as walls, the backdrop to outdoor furniture and activities.

Speaking of activities, there is enough room for play areas, such as horseshoes, croquet (don't laugh. Have you ever played cut-throat croquet on a sloping lawn with gopher holes? Add a few drinks and it's a roaring good time) Perhaps a putting green using artificial grass.

Check out www.synlawn.com - no mowing, no weeding, no fertilizing, no watering. May not win awards for best lawn, but it sure is low maintenance.

Once you have an idea of what activity areas to include and where to put them, then you can start working on plants. Trees and shrubs can go in this month to make "walls", backdrops for activities or to camouflage unwanted distant views and viewers.