While Rhubarb will freeze for later use, if you know that you are going to use it within three months, and have the space in the freezer, feel free to do so. I have dried it, and it does work, and of course takes a great deal less storage space.
However if you are looking to put up large amounts of Rhubarb for year round use for me at least, I like to can Rhubarb Fruit. Please get the Bernardin Complete Book of Home Preserving for all your basic information.
A regular batch for me is 16 cups of Rhubarb to 3 cups of Sugar, and I hot pack it, and hot water bath process for 15 min, so easy! and so yummy when done. You can move your sugar safely down to two cups or up to four cups keeping the rhubarb at the same percent depending on how sweet or sharp you like your rhubarb. It makes me six pints. Is there anything better then hearing that “Ping!”