I took my cousin on last november, for 3 / 4 days a week. He promised me he would be driving within a few months of me taking him on.
Everything was fine for the first 6 months or so, but since June / July he's really slacked off (misses windows etc...), he still can't drive which means I have to pick him up from the station every work day (which is sometimes 10+ miles out of my way depending on where we are working).
He's now costing me money... I can earn more in a day working on my own instead of having him with me... He only really earns his wage, and it's costing me petrol and time etc.. picking him up and dropping him off each day.
So... Last week I gave him 4 weeks notice. Not easy as he is in my family, but it had to be done

That being said... Real money can be made if you can find the right people to employ.
My future plans are to build a solid commercial customer base and employ people to work on this commercial work, hiring a manager to deal with day to day issues.
Andy