You may print out the puzzle, and solve it on paper. However, the puzzles are designed to be solved online. Here are some tips.
To enter the letter 'A' into a square:
Click on the square in the puzzle. The square will become highlighted - its color will change. Also, the color of the surrounding squares for the solution entry will change.
Next type the letter 'A' using your computer keyboard. You should see the letter 'A' entered into your selected square.
After typing a letter, the next square in the puzzle becomes highlighted. You can then type another letter, for example 'D', and you will see 'D' entered into the newly highlighted square.
You may change the direction of this highlighting to go from across to down, and vice versa. To do so, click on the single highlighted square a second time, as illustrated in this animated image:
switch from across to down and vice versa by clicking a highlighted square a second time.
Backspace and delete
To "erase" a letter in a square, use the "Delete" key of your keyboard. As of Dec 8, 2011, you may also use the "Backspace" key to erase characters. (This has been tested in Firefox 8.0, IE 8, Chrome 15.0.874.121 m, and Safari 5.1.1.)
You can navigate around the puzzle by using your mouse to click on squares. It is also possible to move around from one square to the next by using the arrow keys on your keyboard.
About crossword puzzles
Crossword puzzles are fun ways to test and build your general knowledge and verbal skills. The goal is to fill all of the white squares with letters that correctly solve the puzzle.
To start, click on the first ACROSS clue. This highlights a row of squares in the puzzle matrix. Your task is to think of a word (or phrase) which means the same thing as the clue, and fits in that highlighted row of squares. For example, if the clue is "Norse god of thunder", and there are four squares in the solution row, you might type "THOR" into the solution squares.
You may work the puzzle in any order you choose. Some people prefer to work in an orderly way, starting with 1 ACROSS and moving through all the ACROSS clues before working on the DOWN ones. Others prefer to work on a corner of the puzzle, filling both ACROSS and DOWN clues together. It is often most productive to simply skip a clue when you get stuck, moving on to the next clue. As more squares become filled with letters, you may find that the solutions to clues that initially confounded you become perfectly obvious.
We gratefully acknowledge the contribution of Robert T Morris, who wrote the code which generates the crossword puzzle matrices of letters.
Marya thanks Robert Schultz for many helpful conversations. When you've finished solving a crossword puzzle, you may wish to exercise a different part of your brain by playing a game of Solitaire at his excellent World of Solitaire website.
Other fun websites...
If you enjoy more social games, you can play Hearts, Euchre, Spades, and Go Fish on his new World of Card Games site. The site is multiplayer, so you can play with live folks out on the internet. Or you can play with robots. Your choice!
For the mathematically inclined, give Planet Sudoku a try! You might think that solving sudokus online would be a bit painful, but this site lets you add notes to each cell to keep track of your thoughts as you work towards a solution. It's got a clean interface, and some cool background images.