Early reference to the three sections of the Written Torah: Eruvin 17a
The tradition of which words are written fully and which have vowels omitted is part of the Torah itself: Nedarim 37b
Number of Verses in the Torah: Kiddushin 30a; Masoret HaShas Berachot 7a
Halfway mark of the Torah in letters, words, and verses: Kiddushin 30a
The cantillation notes, as part of the Torah itself: Nedarim 37b
The splitting of separate verses, as part of the Torah itself: Nedarim 37b
Verses which are actually split in two: Kiddushin 30a
Verses which are actually split in three: Nedarim 38a
The Bible is made of 7 Sections [Chumashim]: Shabbat 116a
If the Jews hadn't sinned, they would only have needed the Torah and the Book of Joshua, and not the rest of the Prophets and the Writings: Nedarim 22b
Considering the 12 Prophets included in "Trei Asar" to compose one book: Megillah 24a