Welcome, dear reader, to the exciting and complicated realm of runes. You may have seen them in a museum, J.R.R. Tolkien's work, or that one scene in Stardust — they're the little stones with mysterious (probably incomprehensible) symbols carved in them that you draw from a bag or "cast." Those of you who know them from your local esoterica store may equate rune stones with tarot cards — a mystical means of divination with set, designated meanings. But they haven't always been this way. Way back when, "runes" were actually just an alphabet. The earliest runic alphabet is thought to be modelled after the Latin alphabet, and it most likely first appeared in southern Europe among Germanic tribes.
The people most commonly associated with runes are the Norsemen, and, within that, Vikings. Countless artefacts, from gravestones to vases, have been found with rune carvings on them. People used these objects to communicate, pray, and denote ownership. Rude messages have even been found in rune form — yep, not even the Vikings were safe from trolls.
The exact letters of the runic alphabet have countless variations, and it took some time before everyone could agree on how to read them (the final call was from left to right). There's evidence that ancient people wrote out spells, prayers, and invocations in runes, but using them for divining purposes only came later.
While runes reemerged in 20th-century neopaganism and (strangely enough) attempts at diabolical magic during the Third Reich, the process of runic divination that we're most familiar with now was developed by Ralph Blum in the '80s, with The Book of Runes. It has since gone through several other, updated editions, and other authors of esoterica have offered their own, rather different interpretations of the alphabet's soothsaying capacity.
Just like there are different rune alphabets and meanings, there are a variety of ways to read runes, too, from drawing just one to casting a grid of nine. It all depends on what you hope to divine, and whether you're doing it for fun or to answer a specific concern. That said, do watch out for how the runes appear when you draw them. Much like tarot cards, runes can have different meanings when they are drawn in reverse.
Unless you've already dipped a toe into the rune pool, Blum's interpretation of the alphabet will probably be what you first encounter as a beginner. So, take this as your introduction to the world of runes, but don't hesitate to explore which alphabets, sets, and stones speak to you most.