I am told that the Daily Sudoku discussion forum and site may disappear in a matter of months, if not weeks.
The discussion forum has a fair number of decent "how to" tutorials. I think so because I wrote many of them. There is also a substantial archive of puzzles posted by Danny Jones, over time, some years ago.
If there is anything on that site that interests you, I suggest you copy it now.
Forum: http://www.dailysudoku.com/sudoku/forums/
Site: http://www.dailysudoku.com/sudoku/
Keith