You need a canning recipe. Here's what I found:
http://southernfood.about.com/od/jam...r/bl30819b.htm
http://www.recipetips.com/recipe-car...hubarb-jam.asp
http://www.foodinjars.com/2010/04/ap...y-rhubarb-jam/
Hmmmm..... I've got some rhubarb but never thought of making jam with it. May have to try one of the easier methods.....