Here is a tip for saving pea seeds. If you have several varieties going at once make sure you plant about 50 feet away from one another to make sure of seed purity. Bag the flowers before they open. Remove the bags once fruit sets and mark the stems that have been bagged. Let the peas mature on the vine, until the pods dry up, open them and gather the seeds. Do not let pods open on their own. Store them in a paper envelope.
Beans…some people say you need 150 feet between varieties to prevent cross pollination but hard to say. Like peas you simply let them dry on the vine then gather the dry beans.