Agriculture was actually independently developed by several different groups the world over. Namely North America, South America, Asia, Europe, and in and around the Fertile Crescent.

Agriculture spread with people. Migration by groups or individuals with the knowledge brought that knowledge with them to other groups. Trade played a large factor as well.

While I don’t have a specific book reference for you, the subject of early Agriculture and it’s spread is covered in most beginner-level historical anthropology texts, specifically books with an archeological focus.