The accounts from Indian and Pakistani sources both blame the other as aggressor and have very conflicting reports. I don't know which one to believe. Any help would be appreciated.
There are thousands of books on this subject. It's unlikely any one of them in isolation is "unbiased" as all historians entertain their own biases.
The best I have read (of, admittedly, not thousands) is Alex von Tunzelmann's Indian Summer. Veteran historian John Keay's Midnight's Descendants is also a very good survey.
We have a couple of suggestions on our books and resources list.