Keep on the Shadowfell

This will be my first time DMing a campaign. It will be directed to new players who want to get started in the world of 4th ed.

It will be played weekly on GMT+1-friendly times. We'll discuss that as people join.
You can use pre-cooked PCs, but I find it best if everyone makes his own. If you need help, you can contact me to make it. Books used: Everything in D&D world. If it's in the character creator, it can be used (no eberron/krynn/forgotten)
We will be able to extend the campaign if we want, but for now we'll make a basic campaign.
We'll use Roll20 + Skype for the games.

Roles so far: 2 Strikers, 1 Defender, 1 Leader

Realms, both wondrous and dire, border the world. One such realm is the Shadowfell. Although not inherently evil, the Shadowfell is fraught with dangers, and the barrier between worlds can be thin. Sometimes, the darkness breaks into the light.
Nearly two hundred years ago, a cult of the demon prince Orcus purposely created such a gap, connecting one of Orcus' unholy Shadowfell sites to the world. Skeletons, zombies, and fouler creatures flooded through the rift into the light of day. The empire of Nerath dispatched legionnaires to eliminate the threat. The empire's soldiers destroyed the undead, sealed the opening, and built a keep to watch over the location and contain the threat. This is the site known as the Keep on the Shadowfell.
Decades of peace followed, and the village of Winterhaven arose within sight of the keep. Eventually, the great fort fell into ruins and its grand purpose forgotten. Today, it is seen as a harmless tumble of stone and wood.
If only that were true.