Kozen believes in questing to gain levels. This is the quickest way to level. Experienced rewarded from quests is far greater than finding a grinding spots, than killing that same mobs over and over again. The Kozen Guide maps out all the quests you should take from 1 to 50. You will find out where to go for quests, what order you should take the quests in, and how to complete them. So it really is a complete walk-tru of Aion documented in one concise guide.
One of the problems players have found in questing, is that you would complete a quest in one area, then find another set of quests to do in the same area, from another quest giver. This means that you spend time traveling back and forth to the same area. By mapping out the quests in the correct order, the Kozen Guide saves up on traveling time. If you think about it, time spend travelling, means time taken away from doing experience gaining tasks like killing mobs or doing quests. The formula is as simple as that, and Kozen does a great job of implementing this strategy in the guide.