Hiring a housekeeper was the greatest gift I have ever given myself! I have her come once a week for a couple hours and we clean together (much more efficent).
I started by creating a "chore chart" and keep it in my Home Management Binder. This helps both her and I keep track of things that need to be done and when.
Things I have her NOT DO: dishes, laundry, and windows. In my opinon these things are too time consuming to pay her for, but that may not be the case for you.
The things I do have her do weekly are numerous but include cleaning toilets, showers, sweeping, vacuuming and dusting.
Once a month I have her clean light fixtures, doors & door knobs, baseboards, window sills and carpet cleaning.
Basically the beauty of a hiring a housekeeper is that you and the housekeeper can decided to work it any way you want!