and welcome to the forums.
Since it will be your first run with people completely new to the game, you should keep it easy.
It would probably a good idea to talk with them beforehand just to see what they expect and what they want to play.
You could also use the Iconic (pre-gen characters) so that they don't get swamped with the character creation - there are just so many delicious options.
You can find the iconics under: http://www.crafty-games.com/index.php?q=node/851
If you use the Iconics, they can concentrate on the game itself and after they have seen the game in action - which is just awesome - you can walk them through the whole character creation or they go on with their chosen Iconic.
A good start would also to use one of the adventures in "Time of High Adventure".
These steps will at least ensure that you don't have to much on your plate to handle and fully concentrate on the game.
When it comes down to D&D players you have to make clear that there are some changes to the whole system. It's mostly not that much... and many things are thankfully streamlined, which makes FC really easy to run... even if there are some preconceptions that D&D players need to wrap their head around.
Biggest things in my group:
- The Priest is not necessarily a healer, nor a combatant -> he can choose his way according to his beliefs
- The Mage is not the end-all-solution, nor a I-win button... a great thing in my book.
- There are no perfect setups... since you can have Soldiers who fight dirty or a gentleman warrior with a quick flourish of his rapier
- There is also no need to adhere to 1 Healer, 1 Mage, 1 Thief, 1 Fighter... you can have all Fighters and anyone might end up different
- Skills are useful in combat
- Even guys who don't fight can contribute to the fight
- Armor actually reduces damage
- Putting a caster in Armor? No problem.
- Handing the caster freaking big sword? Again, no problem.
- FC is a Toolkit System so you take what you want.
- NPC can be scaled easily with your group. So goblins and other enemys can always pose a threat.
- Biggest one: You can create a character in a way you imagine, without being pressed into a certain role.
Hope, I didn't miss one. In general someone who hasn't played D&D might grasp FC easier than those who have... but with a bit of play they will cherish the whole game.
I hope that helps.