I had a conversation with a young and mid experienced holy priest last night.
She told me that she was training hard in healing groups in different dungeons around Azeroth, she was proud to announce that she had finally visited Blackrock Depths after long hours in the Sunken Temple and Zul'Farrak.
She did complain about some things though.
First off, as the sole responsible of keeping the group alive through the different encounters, she felt that the other group members most times did not understand how the different roles should interact with each other.
First off she had some remarks on some of the tanks that she had trouble with.
Tanks
A person who has volunteered for the Tank role should be prepared to get bashed a lot. The one purpose of the tank is to keep all enemies hitting him or her instead of the rest of the group. So, two things that should be important for a tank is the ability to prove to the enemy that she is the most threatening person in the group. How she does that is entirely up to the tank, the key here is that if the tank is unable to do this the job gets very hard for the healer as she must divide her attention to up to 5 people instead of 1. And damage dealers are unable to focus on their task as there are enemies up close hitting on them. It does not take a goblin engineer to figure out that this is a recipe to disaster.
Another thing that annoys her about tanks is that there are so many people out there that say that they are tanks, but in reality they are not.
"One time I ended up in a group with a paladin tank, no problems I thought as I've seen paladin tanks before and it is usually not problem. But after the first encounter with some enemies I started to think that something was really really wrong with this tank as I had to heal him a lot more then I usually have to even at bosses. After a closer look at his gear I saw that he was a Holy Paladin with a short sword and shield... With almost only Holy gear. I made my excuses and left in a hurry..."
As tanks primary role is to get beaten with a stick, they should have gear that supports this. Armor, Stamina are at least the least one can expect them to stack!
Last thing, if the situation turns ugly, the primary focus of the tank should be to keep the healer safe. Yes, we might loose a few group members but mostly the healer can resurrect them before the next encounter. But if you loose the healer, well, then the whole group is screwed.
And do please keep an eye on the healer, if she is sitting down and drinking.. Maybe you should wait until she finishes up before rushing to the next enemy. A healer that is drinking is probably running low on mana, and without mana, there will be no healing..
Lastly, tanks should study instances… It is commonly assumed that tanks know their way around. If a tank goes the wrong way, the group will become demoralized and eventually just desert.
Damage dealers
I will not divide damage dealers to melee or ranged as this applies to both. Very general ideas and thoughts.
"I have spent some time with damage dealers that do not understand the dynamics of group roles. They have no clue of how to behave in a group and just rush into situations even when the tank and or healer isn't ready. Instant disaster."
It is usually the tank who starts a fight with the enemy, give her a chance to do that. If you start to engage enemies instead of the tank the tank will have a hard time getting the enemy to hit her instead of you. And you want the enemy to hit the tank, trust me.
Do not complain about the speed that the group is progressing in, trust me, let the tank decide the pace or else she will start making mistakes and you do not want that!
As a damage dealer in a group your role is to put down the enemies as fast as possible. But that is not all, each time that you make an attack the enemies will feel that you threaten them more. And if you threaten them more then the tank, they will start attacking you instead. So the primary responsibility is to put down the enemy as fast as possible but still not generating more threat then the tank.
If the enemies for some reason think that the healer is the most threatening one in the group and start attacking her while the tank is busy holding off an other group of them, please get the enemies to attack you instead. A healer who is taking damage has a real hard time keeping the group alive and well. Attack the enemies, let them start attacking you and run to the tank and she will threaten them to attack her instead. Easy task, very easy to forget about.
Oh yes, damage dealers are usually the ones that turn rude against the healer, tanks mostly do not. I will only remind you once, do not be rude against the one person that is keeping you alive! It does not take much for a healer to decide that you are unworthy of her services and you do not want this either as this usually ends with you dead and the healer asking "did you say something?"
Healers
"Ok, I may be a little biased here but I will try to analyze myself a little"
Healers are responsible for the safety of the whole group together with the tank. They are usually not seen as a part of the group but they do provide services that everyone requires.
Never ever sacrifice the tank, do what you must to keep the tank alive. Know how to use dispels, cures for diseases and every other spell in the book. They are vital for almost every dungeon.
Never ever sacrifice the tank but try to keep the other people alive as well. They are not priority, do not focus on them.
Heal over time makes you life easier, a lot easier. With a great group that is the only thing you need, I've been to Maraudon and only used my renew spell. With an normal group, keeping the heal over time spells up on the tank will make the other spells less frequently used. I can't remember how many dungeons I've been in with Renew and Flash Heal only.
With less good groups you will end up using heal over times on the other members as well and some times a fast normal heal as well.
As with gear, having a lot of mana regenerating stats is a must. A lot of the time you are in a battle, you will not be casting any spells and this time is great to regenerate you mana pool as when things turn ugly, you want that pool to be full.
Do not over heal too much, especially do not over heal other group members but the tank. Only heal when you must (not counting the heal over time on the tank) and save you mana to situations when it is needed. I know that until I figured out how to use my renew spell I used flash healings on all members of the party, this not only drains mana in no time, this also keeps you occupied with casting them.
If the tank picks up rogue enemies from your team mates when ever they stop focusing on her, they usually only get in a blow or two and you can heal that with an instant heal over time spell. Using a long cast spell on other members then the tank when it is not needed makes you loose focus as well and situations around the tank can turn ugly very very very fast indeed.
On another matter, it is important for healers to let the tank protect them. If you as a healer get attacked by enemies, get as close to the tank as possible. Never ever run away. If you run away and the tank notices, she will have to run after you and thus it will take her longer to get the enemies to attack her instead of you.
"Whenever I get attacked and there is no one around to take them off me, I tend to run through the battle, clap the tank on her shoulder and get into position on the other side. This is usually all the time needed for the tank to get the enemies to switch focus. Another thing I do, not because I think that it really helps but I like to think that it does... I tend to use levitate a lot on myself, the effect is that I will be floating above the ground as long as I am safe, if something attacks me the effect will fade and I will be on the ground. I like to think about it as a visual cue for the tank that something is happening."
Summary
A good group consists of a good tank and a good healer, the damage dealers do not matter as much as long as they are ok. A group with either a bad tank or a bad healer is a group that will end up dead. A group with a great tank and a great healer will mostly be ok and can make up for mistakes made by the damage dealers.
A group with a great tank and a great healer and great team players as damage dealers will not be stopped.
Know your role, know your expected behavior, know your limits!
Yes, the famous quote of the Orc peons. But could it fit better to our daily lives? 
Each role in your empire will need to know the current prices and fluctuations on the market and it is up to your banker to supply them with that information. Each role will want to know the current prices on materials as well as the products that they can create with these materials. They are the ones with those lists so it is up to them to decide what products will be most profitable, but you will need to bully them to not create too many of each product as that will, in the long run, make prices drop. Keep rare items rare! This is easier to say then do as everyone will be tempted to create 10 red pirate shirts as they are going for 15 gold each.. But if you have that many of them out at one given time, chances are that there will be other people noticing your product. Well, you want other people to notice your products but you do not want your competitors to notice them as they will start creating the same items and undercutting your prices and in no time the whole market for that product will be in a downward spiral.
