Like the Pharisees, the Sadducees were a Jewish religious and political party that existed during the life of Christ and the beginnings of the early church but disappeared soon afterwards. If we know little for certain about the Pharisees, we know even less about the Sadducees.
We know, from the accounts given in the Gospel and in Acts, that they denied the physical resurrection of the body and were skeptical concerning angels and other spirit beings. It is perhaps likely, though not certain, that they accepted only the five books of Moses as Scripture and that this limited canon may have been connected to their rejection of a bodily resurrection.
We know that, at least during the ministry of Jesus and the earliest days of the church, they were associated with the high priest and his family. There is some evidence to suggest that they were associated with the high priesthood more generally, but it is impossible to be certain. We know that they disagreed with the Pharisees on a wide variety of issues even while representatives of both parties were members of the Sanhedrin.
The general picture we get of the Sadducees is of a group that was more concerned with their power in this world than with their standing in the world to come. In the end, they, together with the other leaders of the nations of Israel, colluded with the Romans in putting Jesus to death.