I learned a hard lesson way back at the beginning when I employed someone throu the jobcentre. She was as nice as pise, had good references from previous cleaning jobs and I thought I was doing the right thing. She lasted 3 weeks, was completely useless, took a day off with all sorts of excuses every week and lost me 2 clients.
I made a vow never to take on anyone who I didn't know, or was recommended to me. AND I also make sure that the people I employ actually love cleaning. To them they are earning a few bob from doing somwething they enjoy.
I have 4 regular girls and 2 that step in and they have all been with me at least 6 months up to 2 years. I do have the odd moment with the youngest who is 18, and sometimes she 'forgets' to clean behind a door or under a table, but apart from that she is a good cleaner.
I also have one who occassionally lets me down at the last minute, but again she is an excellent cleaner and fast too.
I make sure I get to know them personally, and think it is as important to be their 'friend' as well as their boss. If you know as much about their personal life (because you have developed a good personal relationship) as you do their working life you will know if they are pulling a fast one.
Some people say don't employ friends or relations etc, but it has worked for me and is still working