The Character Builder is the single best thing for you to use.
Your players are not new to D&D, so you can quickly go through the creation of the character with the software for level 1. The great thing is they get all their powers printed out relatively neatly.
When I started
4e, I wasted a lot of time looking at all the options for my newbie players.
Also:
- Make sure they know how to use the Action Point, and encourage them to use it.
- Give them a new action point every two or three encounters
- In every encounter, let the monsters do something stupid that makes at least one player make use of their special powers. For example, monsters attacking someone else when marked by the fighter. He'll be happy to attack.
Or have minions lined up to be roasted with burning hands, or undead for the cleric, etc.
Happy players are good players. First impressions count.