Below are listed some of the major 'spirits' that are mentioned in 'Germanic' culture, indeed some are considered worthy enough to be named among the Æsir. I would direct you to some of the sites on our Links page for a more in-depth account of them.
Ælf
aka Ylfe, Ælfar, Elf
This Englisc word survives as Elf. In Old Norse they are often named alongside the Æsir, apparently connected to the Vanir, we are told that Frea was given Æ1lfheim ("home of the elves") as a gift upon receiving his first tooth (where the tradistion of the Tooth fairy originates). It seems that they lived in mounds, are linked to healing, and are prayed to during childbirth, it is also believed that diseases are caught through "elfshot", tiny darts or arrows fired by dark elves (rudimentary knowledge of air borne germs?).
Alaisiagæ
One of the Wælcyrige
Alvit
aka Hervor, All-Wise
A Swan Maiden who takes human form and becomes Welund's lover
Brunhilde
aka Brynhild, Brynhildr
One of the Wælcyrige, imprisoned by Woden in a ring of fire, within which she fell into a deep sleep, she is the lover of Sigurd (whom she had killed, when she thought she was deceived by him), she eventually kills herself with remorse at Sigurd's death.
Disir
Female ancestor or fertility spirits.
Eldir
Servant of Ægir.
Frimafeng
aka Fimafeng
Servant of Ægir.
Glum
Attendant of Frigg.
Gna
Emissary of Frigg, traveled through the sky on her steed Hofvarpnir.
Goll
aka Screamer
One of the Wælcyrige.
Gondul
One of the Wælcyrige.
Gunnr
aka Guðr
One of the Wælcyrige.
Groa
Seeress & concubine of Aurvandil, she tried to heal Þunor after his battle with Hrungnir.
Gudrun
Wælcyrige, fell in love with the hero Helgi, when he is slain in battle she weeps so much he calls from his grave to plead with her to stop, they will be reunited in Valholl.
Hildr
aka Battle
One of the Wælcyrige.
Hladgunnr
One of the Wælcyrige who sets traps for her victims.
Hlokk
aka Shrieker
One of the Wælcyrige.
Hyndla
Volua who accompanies Freo.
Ilmarinen
Finnish hero who hammered out the sky with his magic hammer at his forge & accompanied Vainamoinen.
Kvasir
aka Spittle
Wiseman slain by the Dweorgh's Fjalar & Galar & turned into a magic mead in an attempt to gain his wisdom and the gift of poetry, this mead was eventually drunk by Woden instead. He was created from the spittle of the Æsir & Vanir, who spat into a jar to mark the end of conflict between them.
Landvættir
Guardian spirits that protect places and lands, the original source for the European habit of having patron saints for countries, i.e. St George, St Patrick etc.
Leminkainen
aka Lover
Finnish hero, a talented singer & pursuer of women who journeys with Vainamoinen. He is slain by Tuoni's son and his remains are scattered into a river. His magician mother then collects his body parts & brings him back to life.
Menglad
A renowned beauty who is wooed by Svipdrag.
Norns
aka Nornir
Demi-goddesses of destiny, they are said to help at child birth when each person is alloted their own personal Norn, where the belief in 'Guardian Angels' originated from. The three Norns dwell by a well which stands under one of the mighty roots of Yggdrasill. Daily they wash the root with water of the well, mixing it with clay, to repair the damage done to it by Nidhogg and the serpents. The water is said to be so 'holy' (Holy water, where have I heard that before?) that 'all things dipped in it become as white as the film which shines within the shell of an egg'. The Norns controlled the fate of men & the Gods by spinning their 'Cloth of Destiny'.
Olrun
A Swan Maiden who takes human form and becomes Egil's lover.
Rhine Maidens
Ethereal spirits who dwell in lakes & rivers, the sagas contain many stories of them, to whom many sacrifices were regularly made, this has developed into wishing wells etc., how many times have you thrown coins into them and fountains? Both Celtic & Roman mythology also contain such spirits.
Roskva
Sister of Þialfi and servant of Þunor.
Rota
One of the Wælcyrige.
Scinna
An Englisc name for a spectre.
Scucca
A Goblin (Englisc) or Svartalfar.
Sigrdrífa
One of the Wælcyrige, mentor of Sigurd, she presents him with a horn to drink mead from.
Sigrun
One of the Wælcyrige, said to be Svava reborn.
Skirnir
Servant of Frea, he is given a horse and sword by his master to use to help him bring Gerda to his hall so Frea can marry her. He eventually tricks Gerda into marrying his master.
Skogul
aka Raging
One of the Wælcyrige.
Skuld
aka Future
One of the Norns. Also listed among the Wælcyrige.
Svava
One of the Wælcyrige, said to be reborn as Sigrun according to some sources.
Svipdrag
Son of Groa, raised his mother from the dead to seek her advise on how to woo Menglad.
Swanwhite
aka Hladgud
A Swan Maiden who takes human form and becomes Slagfid's lover.
Syn
Attendant of Frigg, she is called upon by those on trial to help in their defence.
Þialfi
aka Thialfi
Servant of Þunor, he is beaten in a running race by Hugi.
Þrud
Mentioned as one of the Wælcyrige, this is also the name of Þunor's daughter, possibly just a coincidence.
Verdandi
aka Present
One of the Norns.
Volua
A Seeresses with the powers to descypher dreams. She is called upon by the Æsir to help protect Bealdor.
Wælcyrige
aka Valkyrja, Valkyrie
Choosers of the slain, sister spirits who gather the fallen heroes from the battlefields, originally dark angels of death, they evolve into Woden's shield maidens, they are charged with bringing newly killed heroes to Valholl & Sessrumnir where they wait upon them during feasts. They are said to be beautiful but also have a savage side, the term wicce (witch) in Englisc, may of derived from Wælcyrige.
Wyrd
aka Urd, Fate
One of the Norns.