People ask me for book recommendations a lot, especially when first delving into Germanic Paganism.
3 books I would recommend for constructing a basic worldview within Heathen spirituality (aside from the Eddas and Sagas) are:
– “Gods and Myths of Northern Europe” by H.R. Ellis Davidson.
– “Germania” by Tacitus.
– “A History of Pagan Europe” by Prudence Jones and Nigel Pennick.
These books should help give you a framework for understanding the time period, lives and minds of what we know about the Germanic tribes prior to the takeover of Christianity.
Another book I found helpful was “Sorcery and Religion in Ancient Scandinavia” by Varg Vikernes.
Usually, once a person has worked through these books, they will find a more focused research direction to move in.