Some things to teach them:
1) Raid pacing is vitally important. Keep people moving or they get bored and get up to get a glass of beer, and while they're gone someone else gets bored and grabs a glass of beer. Try to keep things moving and watch the amount of time between wipes and picking back up afterwards.
2) You don't have to do everything yourself. Assign someone else to take care of loot (ideally an officer) so that you can concentrate on what's coming next instead. Assign people to important functions within fights who are not you. That includes doing call outs.
3) Make sure you have the appropriate addons and know how to use them. That includes Grid or equivalent, Skada/Recount or equivalent, DBM or equivalent. Know how to read Skada/Recount between wipes so that you know what happened. Look at World of Logs or the equivalent after the raid. Tidy Plates/Threat Plates also helps more than you might think for knowing what's going on at any given time.
4) Know and explain the fights, but don't be afraid to take advice from others in the raid. Sometimes they've learned something on some forums somewhere you haven't, and it's good to let them have input into the strategy.
5) Don't let the other players walk over you. It's good to let them have input, but in the end it's your decision as raid leader. I've had a few occasions where I had some dissenters in my raid in terms of opinion, but I was pretty sure we were on the edge of success with the strategy we'd been using. I firmly stated that we were sticking with the strat, and we killed it the next attempt, after which I see in /raid, "THAT'S why Reev is the raid leader."
6) Know when to take a break or move on. If you're beating your head against a wall for 2 hours without visible progress, or worse, regression, stop and take a break. Make sure to tell your raiders to get up and move around a lot. When people don't move for a long period of time, their mental concentration starts to wane. Doing a few jumping jacks or situps or whatever can help this problem immensely. When you come back from the break if the problem is still happening, evaluate if it's an issue with execution, or if you need to fundamentally re-evaluate the strategy. If strategy re-evaluation is in order and you don't have any ideas right now, you can always move on to an easier boss to get the morale up and look at the strategy before the next raid. Which leads us to:
7) End on a positive note and give homework. Even if you've had a shitty night wiping, make sure that you frame it as a learning experience and give the raiders some homework on how to study up. Emphasize that they shouldn't just look at one video and stop there. Most of the best information is found in the posts surrounding the videos or on class-specific forums. Getting a diversity of ideas and discussing them on the guild forums before raid time is extremely useful.
8) Look for the strengths and weaknesses in your raiders. There are some raiders that I know are very situationally aware and know how to move/click things at the right times, but I wouldn't trust them to kite anything if the guild depended on it. Know the players' capabilities and you'll save yourself a lot of heartache. This includes how players take criticism. Some people respond really well to yelling and view quiet private talkings to as weak. Others see any critical comment at all as a personal attack, and the only way to keep them in your raid team is to criticize them only in private. These may all be valuable members of your raid team, and there is no good one-size-fits-all approach.
9) Praise your healers. They need it and deserve it. They are quite possibly the least visible factor of success, yet probably the most important. Make sure they know damn well you appreciate them.
10) Realize that success isn't instant. I had a few players the other day complain that we'd spent 2 nights wiping on Cho'gall and that we were totally failing as a guild. Bullshit. It takes time to learn the execution on complex fights. Don't let other people's unrealistic expectations throw you. Make sure they understand that it's normal to wipe and to learn over time.
11) Don't put up with Prima Donnas. Players who think they're better than the rest of the raid and state it publicly are a drag to raid morale. Make sure they know what they're doing, gently, and if they continue, kick them. If they want to act like that, they can do so in some other guild with their "leet skills." Never let another player hold your guild hostage. No one is irreplaceable. There are ALWAYS people looking for guilds, and if you have to, you can PuG the 1 slot while you find your next great player. It's not worth the drama to stroke a Prima Donna's ego.
Kathy, I said, "I'm lost" though I knew she was sleeping
I'm empty and aching and I don't know why
Counting the cars on the New Jersey Turnpike
They've all gone to look for America