Holy information overload TK! Haha! If you're new and just want to limit the damage so games are more competitive, I think there are several things that you should focus on and it's all about keeping it simple. I'm sure some will disagree but here goes.
# 1) Screw manual goalie, unless it's a breakaway. You need to get your team defense in order first before worrying about that. If you're getting scored on like crazy, the best way to stop the bleeding is better defense with your players. The low to mid slot in your defensive zone is where you want to wage war and protect.
# 2) Put an agile, (3 or 4 speed) player on center. Your center is like a 3rd defenseman, use him to force players wide, clog the middle of the neutral zone, back-check with and protect the mid slot area. Super fast skaters on center will make it harder for you to control them, you can end up over-skating on the attack and skating in circles.
# 3) Get rid of the puck at the right time. If you're getting pounded, you're probably not getting rid of the puck (passing it) in time and succumbing to checks from the opposition, leading to change of possession. If you wait till the last second to get rid of it, it's risky and may not work. Skate it until you're about to get attacked, then deke or pass.
# 4) Don't skate in a straight line when carrying the puck. Skating in a straight line allows your opposition lots of time to line you up and crush you or just angle you off till you run out of room.
# 5) Shoot the puck and crash the net immediately after. Many of us, regardless of skill level, look to make that perfect one-timer play or highlight reel deke. But ripping a slapper (even if you don't think you can score) or even a decent wrister can cause confusion of the opposition's defensive positioning, and goalies are known to dive all over the place frantically like they're trying to catch a butterfly with their bare hands. In other words, focus on getting ugly goals too.
In terms of checking, I agree with TK here, stick to mostly B-checks in open ice. C checks usually work (regardless of weight) when you're hitting a guy who is up against the boards though. I also agree with his idea of playing (practicing) against the computer goalies. I like what Smoz says about patience on F and D, and also about not passing into crowded areas (forcing it even when a man isn't quite open enough).
I think for practicing 1 on 0 against computer goalies, play shootouts vs the computer and try out lots of different techniques to score. And you also get to play manual goalie in shootouts, which is a great platform for gaining experience with goalie control with no risk.
TK's videos are good also and showcase a lot of reliable scoring methods. Pick one at a time and work on it, in shootouts and games vs computer. When you think you have them down, start incorporating them in games vs humans.