Like others said: pick the rules that you're comfortable with. You have a big pro to most of us and that is that you do know the rules. For fresh DMs to pick up the books and just start without knowing anything is much harder.
I would keep it simple with their characters. You should probably do a round before you start playing asking what each would want to play. Then go ahead and sculpt the character for them (fill in the sheet etc).
After that you just go for the game. Drag them into the story. If an opportunity comes where they'll need their sheet, you can tell them.
This way, they'll learn to read their sheet one step at a time, at moments where they'll actively use the information you provide. It will be easier for them to learn their way around the sheet and the game mechanics if you pick this route.
If they enjoyed it, they can always create new character that suit them better at a later moment.