Super Saiyan

"The ultimate Saiyan warrior that surpasses the limits of a regular Saiyan. Originally, the existence of this form outside of legend was doubted even among Saiyans, but in reality any Saiyan that posseses a high battle power above the standard level is capable of becoming a Super Saiyan. Possessing a calm heart, sensing extreme danger, feeling strong anger or sadness, or a danger to the Saiyan race itself seem to be outward states that are the essential keys to transforming. The outward signs of the transformation include an aura, golden hair that stands straight up, and sharp, hawk-like eyes with emerald-green pupils. In addition, a battle power 50 times that of normal is proof of the legendary mightiest warrior."

- Daizenshuu 7, Special Attack Dictionary

Overview
According to both the Daizenshuu no. 7, and the Super Exciting Guide, this form gives the user 50 times their regular battle power, although this can be boosted by 'amping' up the users ki output, resulting in the Super Saiyan grade 2 and 3 forms. After unlocking this transformation, the user can further unlock transformations such as Super Saiyan 2 and Super Saiyan 3, through rigorous training.