"Into the New World", was initially released as Girls' Generation's debut single, on August 2, 2007. The group started promoting the song on the SBS's music show The Music Trend on August 5, and subsequently had it reached number one on Mnet's M! Countdown on October 11. Over 100,000 copies of the single were sold.
The second single, "Girls' Generation", written and produced by Lee Seung-Chul and Song Jae Jun, was released on November 1, 2007. The song was originally sung by Lee Seung-Chul in the 1980s. The original singer later appeared on KM's M!Countdown with the group to perform the song together. It was also used in episode 76 of You Are My Destiny, a drama that starred Yoona.
In early 2008, Girls' Generation began promoting their third single, "Kissing You". The song won the group their first K-chart win, after achieving the number one position on the KBS's Music Bank February chart. It also achieved the number one spot on three major TV music rankings: SBS's Inkigayo, Mnet's M.Countdown! and KBS's Music Bank. The music video for the song contained scenes of the Making of video of the Girls' Generation MV, and footage of the girls working on their first album.
The fourth single, "Baby Baby" was released on March 17, 2008. It was the lead single of the repackaged album of the same name.