I'm not a Witnesses. I'm a historian. Personal narratives tell the story as the author would have it, not always as it is. Approach them all with caution, both the favorable and the unfavorable.
The Witness religion is bibliocentric. They will answer from the Bible because their beliefs are derived from it. This is not to say that everything they see as Biblically correct is so. But they think it is, and when they explain a belief they will do so from the Bible. Take the Bible from the equation and the religion has no reason for being.
A more neutral approach - and more scholarly approach - to Witness belief and practice are Zoe Knox's Jehovah's Witnesses and the Secular World and George Chryssides' Jehovah's Witnesses: Continuity and Change. Neither book is totally free from error, but they are largely so, and both are written by scholars with an academic rather than polemic interest. Both books are very, very expensive. I recommend Interlibrary Loan.
If you want something that details the very earliest years of the Watch Tower, then I recommend [shameless plug] Schulz and de Vienne: Separate Identity, vol 1. This is not nearly as expensive.
Approaching the study of any religion though the work of disaffected members or anti cult activists will mislead you.