Which handgun would you recommend to someone with little or no firearms training or experience, for home protection?

12 gauge auto w/00 buck.

I have an S&W MP 9MM I love it. My Wife has a S&W 380 body guard it's small and light.

IMHO a revolver with a thumbcock hammer (some don't have them) They are about the safest and easiest to shoot...you either have to thumbcock it or pull trigger really hard and you don't have to rack it to get a round in the chamber...and they are pretty accurate. I would say a .22 magnum or even a snubnose .38...easy to load, maintain, and fire. Not too much to think about.

Now...of he is willing to to get a small shotgun, My mom has a double barrel (side by side) .410 she keeps for protection in her closet...all she has to do is to point and shoot...doesn't really have to aim real well.

We live in a rural county. The sheriff told us that unless the moon and stars align perfectly, we are looking at a 7-18 minute response to a home invasion.

Home defense
1) Barred rock rooster and 5 geese guard the exterior.
2) Big ass, large, barking dogs (four of them) buy us time to get our wits about us, and arm ourselves.
3) Revolver. For the same reasons you stated.
_I like less lethal rounds. I don't necessarily want to hit what is on the other side of a wall. My grand kids visit a lot. I want the bad guy in the same room as me when I poke holes in him. I will keep advancing so he ends up with flash burns from the last round I put in him. No science to prove it, but five or six holes from a .38 all delivered within 12-16 feet as fast as I can pull the trigger should be pretty effective putting down the target and the accomplice has less than 3 seconds before I recharged with my speed loaders. Three seconds is along time to decide where else is a better place to be. If my wife is home she's a foot behind me slightly offset and covering me when I reload. We practice every two weeks.
3) Strategically placed hand to hand knives and bludgeons.

I don't like long arms for home defense. We live in a farm house. No room longer than 12' and no interior doorway wider than 28 inches. Long arms are too unwieldy in my case.

45 and get some training. As a warrant in schaebisch hall I was the PBO for 180th aviation. I qualified with a 38/45/m14.

I got mine at the PX the people behind the counter were talking to some folks who had very little if any experience with a firearm and they really made sense and were very helpful.

I have an S&W M&P 9MM. Great gun. If you want on to conceal carry look at the 380 Body Guard my wife had one I have the biker style wallet it will fit inside my wallet.

DON'T BUY ANYTHING YET. You should be able to find a local range that has rental guns to shoot at the range. You can get your training and at the same time find the hand gun that fits you right. There is so much more then just the brand name that affects the ability to use it accurately. Your strength, hand size, eye sight all impact the end results. Sure you can spend a lot of money and buy a Kimber or save money and get a Taurus, you have to be comfortable with what is in your hand and how well you can shoot.
Finally, unless you are ready mentally to kill an intruder, don't get a gun. If you pull out a gun, you automatically escalate the tension of the situation. The suspect may not even have a gun, but if they see that you can't pull the trigger, they may take it from you and use it on you and your family. If you aren't ready to pull the trigger, use the money to make a safe room that you can lock the door and keep the bad guys out. A steal door with locks on the bed room will cost about the same as an average 9mm

Like several have already said, go with a shotgun loaded with #6 or 7 shot. Less likely to go through an interior wall and injur or kill someone that is not the intended target. For someone with little training in firearms, a shotgun works wonders since it can be a very effective point and shoot weapon.

Semi-Auto shotgun. Alternate rounds with birdshot and buckshot.

Remember that these rounds WILL go through drywall. Know who is where in your house.