When the pods turn brown you can pick them and let them dry completely in a dry spot indoors. Shell out the seeds and clean and sort them, discarding shriveled ones and ones with holes in them, and put them in paper envelopes to keep them dry until next spring.

Thanks Tugbrethil, I thought they might need to be treated that way. I will have to cut the plants and hang them to dry under cover. Things don't dry well up here naturally. The cold and damp nights creates havoc on allowing things to dry. All my other beans and peas I have to pick the pods and dry them indoors.