Runes are used for divination, spelling, and much more!
Runes can be used to divinate the future or get a sense of direction in a current situation. I've done some divination with runes myself. There's rune casting, the act of taking a handful of runes and "casting" them out on a white cloth. There's also different layouts for rune divination. I, myself usually use the past, present, future layout. Sometimes I only cast one rune to see what it holds in store for me. Sometimes divination with runes(or anything really) can be a bit difficult to understand. Let me give you an example.
I cast out the rune Fehu. When I cast it out, it is up to me on how I interpret its meaning and apply it to my current situation.
Lets say you wanted to make a poster dedicated to Odin and wanted to include runes. You want to spell out Odin, right? For that, you need to know what runes stand for what alphabetical letters. To spell out Odin, you would spell out these runes in this order.
Othala, Dagaz, Isa, Nauthiz.
I've even spelled my name in runes. You can write in runes for a spell or some kind of devotion and burn it to either activate the spell or to devote.
Sorry this was so short! Feel free to contribute.