Welcome to Norwall!
This is my D&D campaign inspired by my interest in the upcoming D&D Next game. As the first fantasy game I’ve done in quite a few years, it’s intended to be a fairly generic, run-of-the-mill fantasy milieu. That is, there are no specific twists or changes that would separate this from any number of standard D&D campaigns.
The two biggest differences will be in the organization of wizards, and religion will be a bit different. One of my biggest concerns when putting together a fantasy world is internal consistency especially with regards to magic. The level of magic found in most D&D campaigns would completely negate the need or usefulness of castles and armies, and it would be hard to explain why wizards aren’t ruling everything. Even at a societal level, the presence of clerics would make death rates far lower than they would be in a real medieval world, thus leading to a much larger population, which would have a huge impact on the culture.
Religion is another point where fantasy typically diverges significantly from historical medieval models. Monotheism was the rule in medieval Europe, and the Church played a very significant part in the history of Europe – both for good and bad. But in most fantasy games, polytheism is the rule, and the churches of these “gods” are far less influential than the Catholic Church of history.
After that, take a look at your wiki. There is some more helpful info there.