here are the first things that come to mind:
i enjoy learning about various religions from the point of view of ordinary practitioners, who are feeling out how to live their beliefs in daily life (spiritual memoir books, i guess). a favorite of this genre:
Things Seen and Unseen: A year lived in faith by Nora Gallagher
She is Episcopalian. one of my favorite books of this decade. through her searching and wrestling, serving in her community, she uncovers for herself her core beliefs.
my favorite book for explaining the core beliefs of Buddhism:
The Heart of the Buddha's Teaching by Thich Naht Hanh
(Buddhism for some is their primary religious path, while other people of different faiths can benefit from Buddhist teachings on the practice of meditation.)
Islam: The Straight Path by John Esposito gives a very good introduction and is likely available in your library.
trying to remember the exact title for my fave Judaism book....all i'm thinking of are heavy books.
i am interested in (but have not yet read) The Faith Club, about 3 mothers, one Muslim, one christian, one Jewish. i expect it would reveal the commonalities and differences among these faiths.
best wishes in your seeking and learning.