The yard does not slope a great deal, but enough to notice...maybe 6
inches every 15 feet or so? I am going to fill in the low side to make
it level with the high side -does that make sense?

Ideally, your yard should slope away from your house. This allows rain and
roof runoff to drain away from the house instead of ending up in your
basement/crawlspace.

However, I understand you are installing a patio.

I am not digging very deep here - only enough to uproot the grass

If you're only doing a small area, you can dig up the sod using a square
edge shovel. If you have a larger area, rent a "Sod Cutter". It makes the
job much easier. We took out a lawn a few years back to put in a new
driveway. The sod cutter worked great.

It will be a brick patio.

I'm guessing this is up next to your house? If so, I'd try to avoid digging
down, and concentrate on filling the low areas. I would remove the sod and
any loose topsoil. Then lay down a layer of gravel for your base, and level
the area using the gravel. This will work nice for leveling, and will
still allow drainage. Rent a "plate compactor" to tamp down the gravel (You
walk behind them, kind of like pushing a lawnmower), then lay down a layer
of sand and compact that too. Lay your brick, sweep sand into the cracks,
and run the compactor over the bricks. You'll probably need to sweep more
sand into the cracks.

Depending on the elevation diffence at the edge, you may have to build a
"step" of some type. Or, bring in fill dirt to bring the yard up to the
level of your new patio.

Anthony