The problem you will have when you first start employing, is getting the best out of your workforce and make a profit at the same time.
Remember that it will take them months to get to your speed withthe quality of clean you require, so for instance if you can clean 4 average propertys an hour, a newbie will only be able to do between 2 and 3.
So if your minimum charge is £12 per house and you pay £10 per hour, so with all the extra costs in employing (tax, ni, sickness, holiday and from next year for some companies Pensions) you will be paying out over 50% in wages.
The other problem is when they are doing nothing because of weather or breakdowns, do you send them home without pay or pay them to "push a broom around".
What I found works best is to pay a salary based on 3 to 4 days work at the minimum wage, and every 2 months pay out a bonus on the work done.
I then increase the salary rate to 4, 5 and 6 days when they can actually do what I can.