It's not to early to start thinking about and planning for the end of summer.
In the fall, it is time to start collecting seeds for next years garden. It's easy to collect seeds from most annual and perennial flowers. After the seed pods turn brown, you can cut them off or even just tap them over a container. Be sure to label them so you will know what they are when its time to plant.
When you're finished collecting, you can make your own seed packets to trade with others. You can find seed trading groups on Facebook and other internet sites. This is a good way to increase the variety of plants in your garden just for the price of a few postage stamps.
Save pea and bean seeds by allowing the pods to ripen on the plants until they're dry and starting to turn brown. Strip the pods from the plants and spread them out to dry indoors. They should dry at least two weeks before shelling.
Good luck!