http://www.trailcooking.com/dehydrating101/beans-legumes-and-peas

You can cook the beans any way you prefer (I like doing them in a slow cooker!). Just drain and put on cookie sheets. In an oven dry on the lowest heat setting, prop the door open a crack with a heat safe spoon (like wood). Check after an hour or so and then every 30 minutes give or take, stirring as needed. Parchment paper under means no sticking. Once dry (break a bean open with a fingernail to check), let cool and the pack up. Dried properly you have a good year of storage time!

PS: even if they crack or get powdery when drying they are still edible. You can whirl the dried beans to make bean powder which you can use to thicken up soups and sauce btw!