A few quick notes on Germanic culture of the day (or at least our version of it) . Your characters aren't bound by these norms, but they are the most common outlooks they will encounter among other Geats, Danes, Jutes, Heathobards, etc. I'll probably add to this as I think of stuff or you ask questions
Death in combat is a goal, not a tragedy, and it is celebrated (on behalf of the deceased), rather than mourned (though the effects of that death, such as leaving children orphaned can certainly be mouned). Death in one's bed, from old age or sickness is considered a curse.
Honor and pride are hugely important - insults are almost never easily laughed off or forgiven. Coupled with the first part of the above point (the celebration of death in combat), this leads to fequent duels to the death over honor. These are neither discourage nor punished.
Family, both nuclear and extended is very important to people in this society - without it
a person is nothing. For this reason, banishment is considered the worse punishment, as it removes a person from his home and people, and strips them of the protections having kin entails. An outcast can be killed without consequence, for example.
Courage, no matter the source (be it inate, induced by drink, etc.) is valued the same. Any attempt not to show fear is taken at face value and others will treat him as if he is unflinchingly brave.
Crimes - theft, murder, insulting a king, etc. are al punished severely, usually by death or banishment. If a crime is commited by an outsider, it must be answered unless a bloor price is paid that satisfies the insult.
Slavery - prisoners taken in battle can be taken as slaves. Slaves have no rights, but are considered valuable, and usually not punished with death for crimes - branding, etc. is more common.
Sex - there's a lot of it, and there's not much thought about it. Both the men and the women are forward about it.
The written word has power, and if you write someone's name in a certain way, you have power over them. This rarely prevents the person whose name was written from killing the person who carved the runes so that power cannot be exercised.
The existence of monsters (especially were-wolves, giants, dragons, and sea monsters) is taken for granted, though neither the PCs nor anyone they know personally as actually seen or encounterd one.
The gods are believed to exist, but they are long-lived, not immortal.
Intelligence (both in terms of education and 'street smarts') is highly valued, and it's use in combat is considered a weapon as much as any sword or axe.