I quit on Christmas eve, when I was on vacation from work. As others have said the 1st 5 days are the toughest and you truly have to want to quit. I was just sick of not being able to run around at the age of 32 due to the fact I couldn't breathe. So I quit smoking then and joined the gym. Been going steady 5 days a week to the gym since. Seeing myself going from smoking 3/4's pack a day, to 30 lbs lighter, stronger than I've ever been, and more energy than I've had since 2004 has put the thought of every going back completely out of my mind.
Good luck to you, but if this is something that you really want, you won't need luck because your will power will be more than enough.