Holtby took part in his first Spurs training session on Tuesday after the club agreed a deal with Schalke to bring forward the midfielder's arrival in North London.
The 22-year-old revealed that he feels part of an exciting project under Andre Villas-Boas and wants to make an instant impact in English football.
He told the club's official website: "Ever since I decided to join Spurs in the summer, I had the feeling that I wanted to come here straight away.
"It's fantastic to be here, a huge club, a club that's getting bigger and bigger every year. There is so much quality here, the coaching staff is fantastic, the facilities, it's the full package. Like footballer's say, I'm over the moon."
Asked about the club's new training ground, the 22-year-old said: "It's massive, fantastic. The best I've seen. I'm so proud to be here and to be able to work in such a fantastic facility. It's Champions League (the facilities) and it's now up to us to get there."
The German international could make an immediate Spurs debut in tonight's game against Norwich City at Carrow Road.