"At what age would you allow your teenager to date? And what would be the prerequisites to getting to date? What guidelines should be put in place? I have a 15 year old son who I know is getting to that point and just as a generality I thought 16 would be about the right dating age. Now, I'm not so sure that it's that simple and I have no idea what kind of ground rules to establish and that sort of thing."
This might sound crazy, but talk to your son about it. Ask him what the rules should be, what age he thinks would be a good age to start dating and consider them. By his answers, I think you can get a clear vision of whether he is old enough to date.
If you decide he's ready, talk with him again. Set the ground rules you think will work and perhaps use some of his too or combine the both of your opinions into a rule or two. And perhaps show him some verses in the Bible, do a search together and look for verses that apply to dating and what Godly dating is all about.
Personally, I think 16 is a good age to start dating. One, because you can drive lol. That's points for the parents and the kids. But it really depends on the your kids maturity. Sometimes age is just a number.
I would state some ideas of ground rules but I think it would be best for you to go over them together, come up with them together. But don't be timid, state what you believe and what you will and will not allow. Also, you may have to be frank. Don't be shy. Sometimes as teenagers we need things straight out, to get the point across.
Make sure he knows the rules before you send him out into the world of dating. (

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And I would like to address the issue of one-on-one dating. I think it depends on your childs maturity level. If you feel like your child can handle spending time one-on-one, let them. Spending time in groups is fine and dandy but it is very hard to get to know one another with a bunch of people around. Trust that your child will do the right thing, they most likely will. I know personally, I want to spend time alone with my date sometimes, I don't want to hang out with other people all the time. And I have no hidden ideas either. It's fun to just enjoy each other's company. Although they are teenagers, they are not children. They enjoy having serious talks, to discuss things. To just spend time with each other. Like you do with your spouse and before you married your spouse. If dating is to lead to marriage, you will never really learn anything about that person if you don't spend time with them one-on-one, but that is my personal opinion.
It is up to you to decide what is to happen. They are your child but don't take God out of it. Don't forget Him, He's your child's heavenly Father. Ask Him what He thinks, whether your child is ready or what other concerns you have. Don't sweat it, though. Don't stress. Embrace that your son is growing up, someday he may move into marriage.
Anyway, I think I've typed enough!
God Bless and I pray for you to have wisdom and guidance.
Smile
Oh, and I have to agree that Joshua Harris does go a bit overboard for me also. I suppose God can call you into that area of not dating until you are an adult or into courting, but He may not have that call for all.