Dear Fahad,
If you want to make it over 100 in iBT TOEFL, I just recommend you to go through more books, of course if you have enough time. I name 3 books in 3 different levels that will help you.
1- Basic Level: Longman Preparation Course for the TOEFL Test
2- Intermediate Level: BARRON'S TOEFL iBT
3- Advanced: Cambridge Preparation To TOEFL
and of course my own website as an online source [sEE MY SIGNATURE OR PROFILE]
Anyhow, I think that one source and it be the official guide is not good enough for iBT TOEFL. If you have any other question regarding this matter please feel free to ask.
Good luck!