What kind of people are guided to the right path after reading the holy book?

Answer:

Verse 2 of Chapter 2:
This is the Book; in it is guidance sure, without doubt, to those who fear Allah.

Verses 152-154 of Chapter 7:

Those who took the calf (for worship) will indeed be overwhelmed with wrath from their Lord, and with shame in this life: thus do We recompense those who invent (falsehoods). But those who do wrong but repent thereafter and (truly) believe,- verily thy Lord is thereafter Oft-Forgiving, Most Merciful. When the anger of Moses was appeased, he took up the tablets: in the writing thereon was guidance and Mercy for such as fear their Lord.