You may find it interesting to have a look at the Satipatthana Sutta and see how the verbs pajānāti, sikkhati, and the phrase, ‘kāye kāyānupassī viharati’ (literally ‘one dwells as a body-contemplator in regard to the body’), are used.
Additionally, if you have access to Ven. P.A. Payutto’s “Buddhadhamma” (freely available on line), there is a great section towards the beginning called “Buddhist Epistemology”.
The part titled “Wisdom Development” has a brief discussion of saññā (perception) ditthi (view), and ñāna (direct knowledge).