Instructions
Visit yard/garage sales in your city or town. Many times, people have porcelain dolls that were given to them by relatives or left to them after someone dies. If the person doesn't want the doll, she may sell it at a yard/garage sale.
Check out thrift stores. Thrift stores may have porcelain dolls donated by the same type of people who often sell them at yard/garage sales.
Look in antique stores if you want to find vintage dolls. The dolls found in antique stores can be decades' old and worth quite a bit.
Attend auctions that include smaller items. Most auctions will publish a list beforehand of the type of items being auctioned off, and even include specific items.
Go to department stores in your area if you want to find new porcelain dolls. You can also check websites of some of the major porcelain-doll manufacturers, such as Doll Artisan Guild.