Will this link help?:
It's an overview of french twists and how to make them.
If you'd like to do the Can-Can updo on yourself:
Put up your hair in electric rollers first, it's really hard to put an updo on hair with no curl in it.
Also, forget to wash your hair the day prior.
Up-dos are much easier if your hair has some natural sebum in it. It gives it some stick, so that it won't fall apart as easily.
Take the curlers down and part your hair from ear to ear, grab the hair in back as though you were making a pony-tail, then twist, and keep twisting up to the top of your head.
Insert 1000 bobby pins along the length of the twist, right in the "seam", get em in there good, and make sure that bobby pins cross bobby pins in an X shape. This will give your twist an infrastructure, so that it doesn't all fall down and un-wrap.
Put some bobby pins at the very top as well, but there you won't need so many, it's mostly up the back of your head that they're required.
Now it's creative, working back to front, wrap sections of the hair that is hanging down around a finger, so that you have a loopy curl, and pin that into the very top of the twist, keep looping and pinning, piling curls on curls, remembering to cross bobby pins whenever possible.
Have a picture in front of you, so that you know where you're going with the style, and don't use much spray until you're all done. After you're done spray as much as you like, but while you're still working, you need your hair to stay flexible.
Don't worry if it's not perfect, it will look better a little free.