This is George Dasent's classic collection of Scandinavian folklore.
This is not about Norse mythology per se; so if you are looking
for tales of Odin, Loki, and Freya etc., you will have to
look elsewhere.
Rather, this is an anthology of folk tales, similar to the Grimm Brothers,
or Campbell's Popular Tales of the West Highlands.
All of the usual suspects are in place, including giants, trolls, witches,
evil step-siblings, magical boons and tasks, and anthropomorphic animals.
The introduction is exceptionally well written, and places various magical
and other themes from the tales into the context of ancient Norse Pagan beliefs.
It is a victorian scholarly treatise
however (with the requisite multipage foonotes and rhetorical flourishes),
and will mostly be appreciated by academic readers.
Once you get past the introduction however, the prose descends
to the young adult level, and the delightful stories can be appreciated by
readers of all ages.
There is also an appendix which has a few 'Anansi'
stories from the West Indies.