An author is a person who writes and sells books.
The person who sells drink is known as sellsmen
baker
A person who sells books is commonly referred to as a bookseller or a book vendor.
You call a person who sells flowers a (Florist)
A person who sells ship supplies is called a chandler
A person who sells jewels is called a jeweler.
A realtor
fishmonger
A chandler.
A butcher.
jeweler