Seed pods should dry on the plant. Surface sow on sterile moist medium and keep covered with clear plastic wrap until they germinate. Never allow them to dry out. It may take months to get a big enough plant to blooming size. It is a lot easier to buy tubers or plants than raising from seed unless you have extreme patience. T&M, Park Seed, and Antonelli are a few places you can buy seed but I've had poor success with most. Fresh seed is the best way to go so harvesting your own may give you a lot more success.

Check some begonia sites for growing from seed.

Brad's Begonia World is a good place to start.

hcmcdole;
thanks for the link, There seems to be a lot of info there, I'll check it out.