Top Sudoku Sites

Here are our picks of the best websites for Sudoku fans, so whether you want to find out how to improve your sudoku skills or just want to know more about sudoku, here is where to find out.

Sudoku Strategies & Tactics features an extensive sudoku-solving tutorial: menu links to explanations of Locked Set, Claim, Fish, Unique Rectangle, BUG+n, Chain, and Smart Fork Tactics. More than 50 full-grid examples.
Solve Sudoku (Without even thinking!) is a good Sudoku tutoral on simple method for solving the puzzles.
Simetric give you two Sudoku tutorials, one is a step by step solution for a puzzle printed in The Daily Telegraph, the other is a seven page tutorial for a 'fiendish' puzzle printed in The Times.
Su-Doku.net Great all-round sudoku site with daily puzzles to play online or print off, information and solving techiques.
A Sudoku Solver By Roger Hui. From Vector Magazine which is "the journal of the BAA, which promotes the APLs - very terse programming languages derived from Iverson’s mathematical notation." This Sudoku Solver is written in text, so if you understood the last sentence I guess you can cut and paste it, then run it. (Can you tell I don't know what I'm talking about).
Sudoku-Help Plus The Sudoku Puzzler's Perfect Notepad! Not a solver but a downloadable spreadsheet that automatically updates all the available options as you solve a puzzle. Sudoku Help Plus includes 72 puzzles plus some Cluedoku (Alphabetic Sudoku) Puzzles. The site also includes a Sudoku solving tutorial and proposes a rating system for the difficulty of Sudokus.
Wikipedia gives you a bit of the history of sudoku puzzles, with lively debate on the content of the article.