The best place to make Jeopardy games online is jeopardylabs.com.
It is fast & simple to create and the game is saved on the site for later use. It also keeps score for you.
The only trick is to remember where to put the question and where to put the answer. Test it after making a few squares to make sure that you have not done it backwards.
Students have to learn quickly how to say “What is….” if you make them answer in the form of a question.
There are also several Jeopardy templates online if you would like to save games to your computer. There are templates for 10 different games at this site: http://bestteacherblog.com/powerpoint-game-templates/