Daily Puzzle from Chessgames.com
In each puzzle, you are given a chess position from actual play, and told which player had the move (White or Black). It's up to you to figure out the best move in that position.
The difficulty of the puzzles increases as the week progresses, with Monday puzzles being very basic, and Sunday puzzles almost impossible.
To see the answer, just click on the diagram. You will not be shown the answer immediately, but instead go to the game from which the puzzle was taken. From there, you can play through the game and when you reach the position from the diagram you can see the move played in the game.
The move played in the actual game is almost always the solution, although every now and then the correct move was not actually played in the game. On these occasions, the notes to the game will explain what should have been played.