Satyarth Prakash

Absolutely incredible book. Written like a research paper, and quotes from innumerable sources. Highly practical advice on daily routines and practices. Makes a lot of sense. The Content + Q&A format is effective. The author is highly authoritative throughout the book, which is essential since there is information overload in the normal world.
Recommended reading for an exploration into the religions of the world, and going deep into Sanatana Dharma.
Contrary to popular opinion, this book makes a case for equality and merit, rather than complacency on the part of any person.
Many complex Sanskrit terms are demystified in simple paragraphs.
Interestingly, the author recommends this particular order of reading the Scriptures: Shastras, Upanishads, Vedas, and then Brahmanas.
On the other hand, the author recommends avoiding reading some famous texts: all Smritis except the Manu Smiriti, all Tantras, Puranaas, Upapuraanaas, Ramaayaana by Tulsi Das. The reasoning is that they are dependant on the Vedas (supreme authority), and hence it is rather to go straight to the source rather than the subsidiary.