The Gates of Discord expansion contains a set of progressive tradeskill quests that have two goals in mind: 1) provide an easy skillup path to 54 in the target tradeskill, and 2) give you a method by which you learn how to process rare new materials specific to that tradeskill. While not all tradeskills actually use their rare new resource, the quests are great for "free" skillups. And of course there's always the possibility that recipes to use the remaining new resources will appear some day.
Each of the below tradeskills has two versions of quests. In the first version, which we call the "freebie" version, the quest giver assigns you various recipes to make, providing all raw materials you need to combine. In the second version, which we call "collect", you must bring at least three of a dropped item, have another NPC convert them to a refined version, and then give your quest NPC the converted material. They will then give you a different set of recipes, one at a time, and the materials with which to create the items required.
For those tradeskills that received many new recipes in this expansion, you will also be given a book explaining the new recipes along with the materials to start the quest.
For both the freebie and collect versions of the quests, you go through several recipes before the NPCs let you learn to convert the raw material for yourself. In the freebie quests you need to do 100 of each recipe before they let you move on to the next. The NPC will give you the ingredients for batchs of 20, which must be combined and turned in before you can get more ingredients. In the collect quests you do 40 of the first recipe, 30 of the second, 40 of the third, and 30 of the fourth. Here the batches are of 10 which also must be completed before getting another batch. At the end of the fourth recipe set you are taught how to do the conversion. (Even when you know what to combine to do the conversion, it will not work for you until you have been "taught".) This means that the freebie version of the quest takes just under three times as many successful handins (400 total) to complete as the collect version (140 total), to make up for the fact that you don't have to collect any drops.
You can also mix and match doing the recipes for both versions of the quest for a given skill. The freebie quest npc will reduce the number of combines you must do for him for a particular recipe if you do some combines for the collect quest npc at the same time. But this only works for the quests that affect the same skill. The freebie and collect quest npcs also know which of the four recipes you are doing for the other quest giver and will give you the corresponding recipe for their quest. Thus, when you complete the quest for one you have also completed the quest for the other.
Once you are taught to do the convertions of that skill's raw material for yourself, you simply put one of that item in the proper tradeskill container and hit combine. When you first learn how to convert the material, you will get back, on average, 1.5 units, for every unit you convert. (Half the time you'll get one back, the other half the time you will get two back.) While this is less overall than you would receive from having the NPC do the conversions, your rate of return will gradually increase. Eventually, you will always get at least two units of the material back, and once you have become highly skilled at working with the material, you have a chance at getting three units of the material back.
Before you get to the point where you always get two back, you will always get one on your cursor, and after dropping that one in your inventory will see a second appear after it on your cursor if you succeeded on making two in that attempt. When you reach the point that you always get two, you will get two stacked together on your cursor (the icon will have a 2 in the lower corner rather than a 1). After dropping those two together in your inventory, you will see a third appear on your cursor if you succeeded on getting three in that attempt. And then, when you finally reach the point where you always get three refined materials from each attempt, you will simply get three stacked together.
A few more things to note: