It is possible to buy books printed with word search puzzles, however a more flexible option is for a parent or teacher to create the puzzles themselves with the help a computer and word search puzzle maker software. Simply enter a list of words, and the computer can generate a puzzle in an instant! Doing it this way has the big advantage that you can tailor the puzzle, for example choosing words based on this week's spelling list or around class project, or perhaps turning off some of the more difficult directions when creating puzzles for younger kids.
Another important thing to remember is making sure that you have enough ink in your printer. This includes color and black depending on what kind of game you decide to print out. Allow the print out enough time to dry before picking it up, some games will use a lot of ink and it may still be damp when it's done printing.