Even secular homeschoolers like to keep their kid’s aware of world religions, and it can be tough to find material that isn’t *too* religious or with a Christian slant to it. I have a 10-page set of notebooking page that cover a number of mainstream religions in a factual and non-dogmatic way.
The book I used was “The Kids Book of World Religions” by Jennifer Glossop, but any world religion book should have the information you need. I focused more on facts rather than broad (and vague) notions about what each religion “believes in”. These can help with recall after reading the book and to learn important terms and holidays involved with each faith.