The Wars of Watergate and Abuse of Power both by Stanley Kutler give one real insight into the scandal and into Nixon. The first book in particular talks about Nixon's own personality and history and how this played into the events as they unfolded.
There are tons of books on Nixon and on Watergate but Kutler's work focuses on the legal aspects moreso than any others.
I think there are good comparisons to today. Remember much of the world we live in today is very different. In the 70's there were no news channels, newspapers were gospel for the most part, no social media. You read the paper and then watched the network and local news in the evenings. All of this plays into why the current events are so hyper-sensitized. It may seem like they weren't during Nixon's presidency, but that's not true at all. Some of the published work out there can give one a sense of the climate back then. Even the recent news about Sally Yates being allegedly muzzled, the distrust of the news media, the blackening of the press, all these events also happened under Nixon.