Who is Surt?
Surt, also known by the kenning Surt the Black, is the leader of the fire etins. He is considered to potentially be the oldest of all the wights and Gods within the Norse pantheon, and from him comes the line of fire giants in Muspellheim (the World of Fire) and many descendants of etin in Jotunheim. It is said in the eddas that Surt even existed in Muspellheim before Ymir was thawed from the ice (which is the start of the creation story for the nine realms). His wife is Sinmora. During Ragnarok, it is said that Surt will be the Jotun to kill Freyr.
Surt is connected to many other Jotuns and especially the Rokkr. It is claimed that Surt is Lokis godfather and that the two have a very good relationship due to this. Raven Kaldera suggested that Laufey (Lokis mother) came to Muspellheim and crawled into Surts fireplace in order to birth Loki, whom we call Flamehair for his affinity to fire.
Surt is infamously known for his giant, flaming sword that is named Laevateinn. It is said that at the end of Ragnarok, on the field of Vigrid, Surt will thrust his sword into the sky and set the cosmos alight. He will burn down Yggdrasil, the world tree, that connects all the nine realms. This fire is said to burn, destroying nearly everyone and everything, except for a few primal deities and wights (and of course ol Surt himself). Because of this destruction that he causes, he is often seen as a raw and primal manifestation of cosmic law. However, it is interesting to note that his role seemingly switches after he destroys the cosmos. In Snorris Uppsala Codex it mentions that there are many good abodes and bad (when the world is recreated): best to be in Gimle with Surt. Gimle is a hall that is described in the Voluspa as being like heaven, where new life will be created and ruled over by Surt himself. However, it is thought that there is Christian influence in the after-Ragnarok story, so the truth of that is unknown.
How to Honor Surt:
Being that he is a Jotun: hard work, dedication and oaths tend to be the best way to make an offering to him, or to get his attention. However, materialistic things work as well. If you build a large fire, you can throw offerings into the fire and let them burn. Some suggested things are: strong alcohol, berries, fruits, sweets, hardy meats. Surt is associated with volcanoes, so lava rocks, metals, flints, etc are good offerings.
Surts Role in Magic:
As you can likely imagine, being that Surt is a fire-etin he has a strong affinity for fire. Thus, those who few fire as a favorable element and wish to incorporate it into their practice may find that working with Surt helps them learn how. He is thought to be knowledgeable in primal fire, even that within stars. If you are interested in astrology, or in space in general, Surt would again be a wight to consider. Helasdottir suggests that Surt is represented by the constellation Bootes, with the brightest star Arcturus. He can be called upon for similar teachings too: moving heat and energy, whether throughout your body or elsewhere, is something that I have seen him worked into before. This is where Surt can tie into healing: In Norse tradition, saunas were seen as a place where healing and energy work occurred. Surt can be worked into healing rituals, and the use of heat for relaxation, as well as for the energy needed to get into an altered state.
Surt is can be involved in galdr, as there are some runes (particularly the ones associate with fire) that can be sung with him incorporated into it. If you follow Northern Tradition Shamanism, you might find that Surt is involved in the Ordeal Work associated with Muspellheim. You can read an example of that here: http://www.northernpaganism.org/shrines/surt/writing/the-muspellheim-ordeal.html
While Surt is often seen as destructive, and called upon for his strength, he is also the primal spark of creativity needed for many other things. He is also seen as the fire within our souls, from where we draw our inner strength and courage.
Raven Ks Jotunbok