About now you're thinking, leave it to the professionals and I'll just buy new seed in the Spring. I hope not. There are many popular vegetables that are easily saved. Tomatoes rarely cross pollinate and even have their own means of killing off diseases before they are stored. The International Seed Saving Institute has just started listing requirements for individual vegetables.
Tomatoes are the first listing.
You've probably missed a few pea and bean pods when you were harvesting and have seen how easily they go to seed and dry right on the vine, ready for storage. Remember, peas and beans self-fertilize before the flowers even open. Clean the Seed Dry seeds are the easiest to save and clean. Podded large seeds can simply be shelled. Maybe you've seen this demonstrated at an historic village.