NOW: Start dry-firing in 20-30 round sessions 2-3 times a week on "targets" that match what you want to do with the rifles.
In the spring, or ASAP: go to a clinic or class on how to shoot it well, or borrow a friend that is CONFIRMED to know what they are doing with the AR across a broad spectrum of shooting.
Shoot Highpower for a year. Then, shoot 3-gun or similar for a year. (in that order)
Now that you have some working knowledge, it's time to take a class or two in uses of the rifle and deployment in situations that interest you, or that may be needed.
At that point, you should be about used to the system, and can sit back and evaluate where you want to go, and contemplate life as riflepeople. You may also need to barrels by then, so plan for that.
Meet up with natdscott (or someone like him... or me!) and have them give you a short class on the fundamentals. I'm sure he'd have no problem giving you some pointers and helping you learn how dry fire practice can be hugely beneficial. You can also learn safe handling, basic operation/teardown/maint/cleaning, things like mag swaps, using the sights, etc. from now until you take a formal training class.
Personally, I like to just sit there watching TV with my AR or walk through the house with it. Sometimes I hang upside down blindfolded and take it apart and put it back together real real fast.
I kid. I kid. But seriously, meet up with someone who is an "AR guy" in the near future and have them go over the basics with you. Schedule a class at a range near you in the near future. Once you have a goal to work toward you'll make swift progress.
Feel free to PM me if you'd like. As the first two guys said, it kind of depends on what kind of training you are looking for. I'd be more than happy to give you the name of a few places to check out and see if it's what you are looking for.
But I would recommend that you seek out some training before you go about practicing things that may or may not be right or wrong. If you get training now you will at least then be practicing the things you should, and know you should! You do not want to spend a bunch of time practicing a bunch of stuff only to then go to training, and find out you've been practicing the all of the wrong stuff for however long before you went... At least that's how I look at it! Not only will it save you time but it will most likely save you money as well.