Growing vegetables from seed saves the cost of at least some of your food. And if you save your own seeds, you never have to buy any. Seed saving also helps preserve heirloom vegetable varieties that many seed catalogs no longer carry. You can't save seeds from just plant, though. Avoid hybrids and open pollinated plants such as squash; the seeds won't produce plants true to the parent. Choose heirloom and non-hybrid varieties of peppers, tomatoes and beans to get started as these are usually true to the parent or close enough that the differences are not significant.
Allow the best looking fruit on the healthiest plant to ripen completely. Look for plants that have shown resistance to insects and disease, have full foliage, and consistently produce the largest and best tasting vegetables.
Pick the fruit once it ripens fully but before it begins rotting. Pick peppers once the skin begins to wrinkle and tomatoes before they split open. Pick pod vegetables such as beans and peas once the pod has dried out and the seeds rattle inside.
Split open the vegetable and remove or scoop out the seeds. Place seeds surrounded in gel, such as tomato, in a glass of water for one week or until the seeds settle to the bottom and the gel rises to the top. If the seeds are in pulp, rinse off the pulp.
Lay the seeds on a paper towel in a single layer. Place in a dry area at room temperature to dry out, about one week.
Rub off any remaining dried pulp from the seeds once they are dry. Place in an envelope and seal. Store in a cool, dry place such as a cabinet or refrigerator.