Scandinavian women, to be sure. Occasional other women, but only when they ended up, usually as slaves, in Scandinavian society. And what it is organized about is the evidence.
Archeological evidence, and grave goods. The only grave good that is unisex is blacksmithing tools -- male only -- but women are much more likely to have weaving tools, and much less likely to weapons.
Runic texts. Mostly memorial stones, erected to women, erected by women -- it appears they were often raised to establish some claim to property by the heir's raising one.
Some evidence about colonization. Place names with Scandinavian women's names as elements can point that way, or by their scarcity point the other.
Foreign texts, which may or may not be contemporary to the times. Scandinavian texts, which certainly aren't, but which sometimes have some reason to believe are handed down, and may include some hints.
Full of fascinating stuff.