Saving seeds is a fun hobby but be warned that hybrid seeds may not sprout to resemble the parent plant. Heirloom plants or those that have not been crossed for hybrid vigor will breed true to the parents form. To save tomato seeds squirt the juicy seeds  onto a plate and let dry in the sun. Scrape them off when dry and seal in an airtight jar until spring. Good luck and Keep growing, Marianne Binetti