Game: Sudoku for Dummies

Whenever I'm on the subway, I always see someone with a folded up newspaper, pen in hand, veins popping out of their forehead, trying to scrawl numbers into a grid - they're playing Sudoku. While I understood the basics of how to do it, I have to admit I never understood the point of the challenge, or how to even begin. Sudoku for Dummies is here, but will it make me a logic whiz?To briefly summarize, the point of Sudoku is to fill in the numbers one through nine in each of the nine three-by-three squares (making a large grid of 81 spaces). Each number can be written only once per square, and only once per row or column across all squares. Simple, right? How wrong I was.