Matthew records in chapter 4 that the first four of the inner core of Jesus' disciples were two sets of brothers. Interesting, I think.
Concerning the recruitment of Simon Peter and Andrew, Matthew makes it sound like Jesus just walked up to them on the beach and said, "Follow me", and they did. But Luke fleshes out the story a bit, and adds the details that Jesus actually spent a bit of time with them first, having borrowed their services as "roadies", using their boat as a stage from which to preach, separated from the crowds by a few meters of water. After his preaching, he stayed on the boat while they went out to sea, and it was during this fishing expedition that events occurred that led to Peter's and Andrew's decision to follow Jesus.