Actually... the country was named Pakistan after the Hindustani (Urdu)/Persian word پاك (pak), meaning 'pure'. This was backronymed by Rahamat Ali, a prominent Pakistani nationalist, to contain the NW provinces of Punjab, Afghania, Kashmir, Sindh and Balochistan. Azad Kashmir didn't really exist until the Indo-pak war, and the entirety of Jammu is in india. Saying that the region consisted of 6 warring mountain tribes along those lines is inaccurate too. While there were a few of them in the northwestern regions/modern day FATA and neighbouring territories, they were ignored by the Britons/used to divide the tribes territory, like with the Pashtuns and the Durand Line. Most of the land wasn't all that different from (the rest of) India, other than being Muslim majority instead of Hindu majority. On a side note, Jinnah actually disliked the name, because he felt that 'pak' would mean that there was necessarily a notion of 'napak' (impure), but was later forced to accept it.
Most of my reading has been concerning the history of India, which is a bit hard to cover without going into Pakistan. I haven't read nearly enough to say what is a good account and what isn't, but I would say that going through the books Pakistan Or Partition Of India by B.R. Ambedkar and India Divided by Rajendra Prasad are worth going through, primarily because of their status as contemporary accounts from pre-independence, and hence pre-partition India.