Here you can download empty Sudoku-Templates for print out by yourself. This allows you to redo a Sudoku puzzle in case someone else already filled it out or you made a mistake an want to start over again.
Hint: Use a pen with an alternative color for filling in the preset numbers. That way you can easily see, what numbers are preset and what number you filled in by yourself.
You can download this templates for free and print them out as often as you like. If you have suggestions or comments, drop an email!