This site will contain a large number of resources all related to sudoku, from links to websites where you can play sudoku puzzles online, to sudoku magazines that you can download, to those that you can print off and play.

But first things first... what is sudoku and why is it so popular?

Sudoku is so popular because it is easy to understand, fun to play, and has many subtleties. It is also easy to generate by computer compared to many puzzles, but unfortunately a large number of generators do not create valid puzzles, most do not generate good puzzles, and very few assess difficulty accurately. Therefore hand made puzzles tend to be most enjoyable to solve, though there are a few good quality computer generators that create enjoyable puzzles.

Whether there is an 'objective' difficulty for each puzzle is disputed as different solvers work differently, however the number of possible moves available at one stage and how hard the logic needed to progress at each stage at each possible point of attack seem like the only sensible metric to adopt. However many computer generators assess difficulty purely on the number of givens, or starting numbers, in the sudoku grid - which is a relatively poor measure of difficulty as whilst difficult puzzles will tend to have fewer givens than easy ones, there is not necessarily a correlation between the number of givens and how hard or easy a sudoku puzzle is to solve.

In addition to sudoku, there are lots of fun sudoku variants out there. For those looking for books that explore sudoku and its variants, here are some suggestions for you:

- Relaxing Sudou Book - a book of large print relaxing sudoku that contains 4x4 and 6x6 grid puzzles, perfect for when you want a nice, simple solve and don't fancy tackling a 9x9 puzzle.
- Sudoku A Day Book - 365 puzzles so that you have one sudoku per day of the year, perfect for a sudoku fan as a gift or just as a treat for yourself!
- Large Print Sudoku Book - contains 100 large print sudoku puzzles.
- Consecutive Sudoku Book - a fun sudoku variant that includes little grey bars between squares to let you know that they contain consecutive values: for instance a 3 is consecutive to either 2 or 4.
- Fiendish Sudoku Magazine - a downloadable PDF containing 50 fiendish sudokus.
- Samurai Sudoku Book - if you want a tough challenge, try a sudoku puzzle that has not one but five overlapping sudoku grids!
- 16 x 16 Sudoku Book - Finally, how about trying a larger puzzle, a 16x16 sudoku: here there are 48 regions, 16 rows, columns and boxes, so these are not for the faint-hearted but if you have time on your hands and patience try this challenge where you have to put 1-16 in each region!