Lots of great posts in here! I'll add bit:

Hard disagree with the poster about red dots and lights. Red dots are practically aim bots. Got one on my AR and one on a shotgun. They're so easy to get on target it's like cheating, actually takes some fun out of shooting. :) But if violence comes to your home, there's no such thing as cheating. Unfortunately, a good one that won't fall apart costs a fair bit. Holosun sounds like a great product, never had one. Saw an interview with the owner of this company, and he was refreshingly honest! No, they're not the best of the best, not for Navy SEALS, but they do what you and I want. That's my next purchase.

I hike in some wild woods at night and doing a little practice on drawing and getting on target sold me on weapon lights. I've got a .45 with tritium (radioactive, permanently glowing) sights. And still, that just doesn't hold a candle (heh) to a flashlight. Bonus! The light is a weapon in itself. Going from a dark room to getting 800-1,000 lumens in the face is more than a little disorienting. Yes, it'll give up your position, and yes, it'll blow your night vision, but still... You're not going to pull the trigger on anything you haven't 100% identified, right? Get a light.

BTW, dummy rounds are called "snap caps". That'll be easier to search for. Another thing a poster called for is called a laser "bore sight".

If you're interested in the education aspect, give Paul Harrell a shot. He's universally respected and gives great talks, see for yourself. Paul's close to the end of his journey, so the newer videos are his brother. Seems expert, but it's not nearly the same.