One thing is I totally agree on with MattVan is using Manny as his swing for a RH hitter is about as good as it gets. For whatever reason those clips I used Arod, I can't remember why.
Also I don't want to recommend you do anything without having seen a clip of your son swing, but instead I'll give you what I know and have been through.
One thing you might consider here Furls, and I suppose I wish I had done this a little more is try and learn what you can first and see if it feels right, before you try it out with your son. Step in the cage if you can still hit and get some air under the ball (line drives, flies, bombs). The reason I say this is that many kids aren't as receptive to listening to something from dad. I had a long talk with my kids, and explained that they were going to have to learn from me, I wasn't going to pay for lessons. One problem I see occasionally is a guy tinker too much and the kid loses faith in dad.
Remember that strength will soon hit, depending on puberty. This is a very tough age. My oldest just turned 13, and many of the kids in his age group are well into puberty, and trust me that is huge. There will be instances where you have oversized LL kids who smash homers, yet don't grow that much more. So keep in mind some kids will look like power hitters right now who may not be in a couple of years. I am surprised at how little my son looks right now considering I am 6'1" and the wife is 5'-10", but I started to really shoot up from 9th to 10th grade, and I think he is in the same boat. He has teammates who are 5'10" already with parents not even the same size as us, so hopefully my son didn't get some small gene. Those boys are stronger though.
Nevertheless I do think there are certain mechanical advantages that assist in power generation. I have my own 10 year old and another kid I work with who can hit homers on the majors Little league field, although my son has yet to hit one in a game but just hitting the first one in practice set his world on fire. A good deal of that has to do with the mechanics we work on. But he isn't a perfect hitter by any stretch. I'd say he strikes out slightly more now, possibly from getting anxious with the top hand like the other poster mentioned. He also drives ball more than he used to. Changing things is also hard. I have a bud who wants me to teach his son to hit for power, but this boy is always getting singles and if he happens to strike out he cries, stomps, throws things etc. I don't think he's ready because you often take a step back to take two steps forward.
I'll be up there in Ohio in another month or so and would be happy to give a lesson sometime if I can squeeze it in, but the goal would be more for you to get something out of it so you'd know what to look for. In general I am not freed up enough with time to do hitting instruction as a business, mostly because I coach teams. However my trip to Ohio is vacation time and I don't have to manage a team for a couple of weeks.
Now let me get technical for one minute, but in general what a lot of kids do is externally rotate the back arm out of sequence (before the hips start to open). That mumbo jumbo could also be called slotting the elbow too soon.
Here was my son last year at 12, and watch very carefully his back arm and compare it to Ryan Howards. Please note I am not saying you have to lift your elbow like Howard, but it does help him keep the sequence correct. In Dmiles' number one son, see how the back arm slots before the hips have started to open? Certainly here he can still hit the ball hard but he is now dragging the bat through the zone instead of powering the swing with the hips and the hands.
Looking back I would not use this Ryan clip again because the location is different, however the point is that he slots the elbow too soon resulting in hips/shoulders hands moving in sync. No stretch and fire. Ryan gets stretched and turns the barrel by rotating the foreams, not pulling arms through the zone like my son. I would label my son's swing a bit "armsy" compared to Howard. (they are kids). I don't think this habit is easy to break.
You don't have to have a high elbow (most do except for Jeff Kent) you just need to keep from slotting it any further until that front hip is opening. Always, always always download a clip you are watching and open that file in quicktime because you can use your arrow keys to go back and forth frame by frame. Quicktime is a must when watching swing clips.
So Stretch and Fire can be summed up as: Clear the hips with the hands back (and locked in), and get the hands flat quickly at GO. One guy says "snap the pole" as in imagine you are holding onto a pole in the ground and you have to snap it off just below the hands.
With that in mind, watch some of these guys from the front, and behind them you can see the back arm. In a high level hitter they will not be flattening this bat, or slotting the elbow if you will --- until the hips have fired. Stretch -- Fire. Mike Epstein uses a rubberband to show how if the lower part is stretched away from the upper, it will snap back into place. The resistance of the shoulders from flying open with the hips, is what creates power we see in the MLB swings.
Watch these swings again, in fact pick a few and download and watch in quicktime, frame by frame. Note the front leg opening (can watch either the stripe of pants or knee) either prior to or at the same time the back elbow is lowering as the bat moves into swing plane.
http://coachdm.hittingillustrated.com/surfdawgs/vertbarrel.htm
The big guys have figured out how to stretch and fire. or clear the hips, and snap the pole, or get the hands flat (whatever cue works). Little guys, even the good ones (including the typical above average HS player) probably look a little closer to my son. An exceptional athlete can overcome a bad mechanic for quite some time (well into minors) before hitting a brick wall. So learning this stuff is hard work.
I think the other night another way I put it was the hips should be open at the time the barrel is going rearward (i.e. away from the zone). Every swing on this page exhibits the correct sequence even if the style is different.
Also I have a small thin bat called a Gro-Bat that is little like a broomstick but weighted as heavy or heavier than a real bat. In fact I have a clip of us messing around with it. It also has a sweet spot, and makes it nice to hit golf whiffles.