The first thing you should know about creating a character for this campaign is that this is going to be very, very hard. The story is tight, the plot interesting, the characters well developed...the dungeons confusing, the traps deadly, and the monsters hungry.
As such, creating a character for this game is going to be a little more restrictive than it might otherwise be. I'm going to have to mandate a good mix of classes to ensure your parties success. So far I think we're doing okay, but I might have to nudge you in one direction or another.
Characters will be created using a point buy-in. I'm going with the hardcover's point suggestion and allowing players to purchase 28 points worth of attributes. In a buy-in, all attributes start at 8. You then have 28 points to distribute evenly amongst your ability scores as you please. Aside from your character classes specialty, keep Constitution in mind as a friendly second choice. Your hit points are your friends.
Religious types, be cognizant of the religious limitations noted in the Campaign Precis. It is within the realm of possibility to have a faith not listed as local to the region, but I'm going to need a good rationale. Above and beyond that, be aware that while undead will play a part in this campaign, your feats will be better spent in places besides extra turning.
On a more general note feats, skills, and magic from the Players Handbook, Complete Adventurer, Complete Warrior, Complete Arcane, and Complete Divine will be allowed without question. Feats and magic from other sources will be considered on a case by case basis.
Characters should fit the general archetype of young go-getters from the region described in the Precis. I highly encourage you to establish pre-existing relationships. Your conglomeration as a group depends on your characters 1.) having the will to get out and do things different from the norm and 2.) wanting to change their local environment for the better. Please keep these in mind as you consider character concepts, and ask me if you have any questions.
Finally, and possibly most importantly, I need you to select from amongst yourselves a team leader. I want this to be a decision comfortable to you all, so please make sure and talk this out thoroughly. The leader doesn't necessarily have to be the face, but whoever it is the character and player need to be stand up types ready to make decisions quickly. I will make the pledge now as your DM to ensure that good decisionmaking on the part of your team leader will be well rewarded. I state this because I want the role of leader to be something that both the characters and you as the players come to view as a wise choice.
Please feel free to ask me if I've raised any questions or confusion.