Sudoku Puzzle training

I'm a sudoku player and was finding that my ability was stretched too thin on the Thursday and Friday puzzles so I sought out something to help me learn the strategies a little bit online.  Enter Sudoku wiki.

You have to pay close attention to what it changes, but the strategies of Naked pairs/Triplets and pointing pairs seems to have the most mileage for solving puzzles that you fell the need to guess.  Prior to finding this tool I would review my work against the answers in the next days paper and found that the correct number for a space was often one I wasn't considering for that space, (ie it was a number that could have been in 4 or 5 spaces so I didn't write it down).  In a sense I was finding that I was building myself a box that prevented me from ever getting the correct answer.  If you have any interest, but struggle with the harder puzzles this is a pretty good (though spartan) tool for learning some different strategies.