As above, but also think carefully, I've had some very good apprentices over the years, I've also had some that were useless! My last one was a mates son, I was asked to take him as he couldn't get a 'proper' placement anywhere and although I was only working part time due to ill health it was better than nothing. I took him on the understanding that I wasn't doing him any favours on account of his dad being a mate, he'd either stay with me on account of his ability, or he'd go. To be honest he was the best one I'd had, going in a filthy loft, no problem, brushing up, no problem, working in the rain, no problem, he took all the carp that comes with being an apprentice and came back for more.
He'd been with me about a year and we'd took on a job to wire a small industrial unit, it clashed however with me taking my wife to an event she'd been looking forward to for almost a year.I dropped him at the job and gave him a few things to do, he could go home when he'd done them, he was a decent lad and I could tust him, 'any problems just ring me' I said as I headed off. About dinner time my phone rang, 'done that, what's next?' he asked, he didn't want to go home so I told him he could start wiring the lights, he did. When I got there the following day he'd done all the lights but hadn't connected them up as he hadn't got a tester.
I had him for two years and he was brilliant, in the third year I decided he had to go, there was some stuff I couldn't teach him due to me only being part time, I rang a local firm and spoke to the boss, he was looking for an apprentice but was looking at a new starter, however he agreed to give my lad a go and he was glad he did, he could run rings around the other lads. He is still with the firm, last I heard he'd qualified, got his JIB gold card and done his 2391, they were looking at making him a supervisor.
I guess I was lucky getting that lad, as I said there are some useless ones out there, not everyone can be a spark, you have to have a 'feeling' for the job, it's always risky involving mates in any business, in fact I'd say it's the quickest way to lose friends. If you do go down that route, just make it clear, 'we're mates in the pub, at work we're boss and employee'.