Mad Swede
Auror
OK. Where to begin without causing offence.They were typically only used to write charms on items or for memorial stones or perhaps place an owners name on stuff. When used in magic they form part of the enchantment & in that sense they were magical - but I dare say only when inscribed as part of a spell/ritual. The memorial / commemorative stuff may or may not have had any magical significance depending on the context (and the fact we don't really know for sure in what contexts it may have been intended to carry some magical or spiritual significance). Since some inscriptions date to Christian times, it is more likely that those were not intended to have any magical significance. The Franks Casket inscriptions are Christian for instance (and use a mix of runes, Latin and Old English). In that context they certainly weren't any more 'magical' than the Latin and Old English used alongside them - but things like the Franks Casket are post pagan.
However runes were not used to write extensive paper records, or write anything as substantial as a chronicle or any other extensive work in the same way Latin was used in the early Middle Ages. This may be a limitation of not having paper, or perhaps it was simply a cultural convention that they were only used to engrave metal, wood, stone or ivory etc. There are no extensive Old Norse myths / stories that survive in runic form from the Viking age, except for perhaps short/fleeting references - all that stuff was transmitted orally by the skalds & if it weren't for the likes of Snorri Sturluson deciding to write it all down in the thirteenth century most if it would be lost to us.
Runes were used for writing both formal and everyday texts in Denmark, Sweden and Norway from the first century until the sixteenth century. There are several major legal documents written in runes. One of the best known examples is the so-called Codex Runicus, which was written in the period 1275-1300 and lists the law and boundaries as they then were in Skåne.
Codex Runicus (complete)
The furthark (in simple English, the runic alphabet) changed as languages developed, and there are three major versions known. The replacement of runes by the the latin alphabet was very gradual and here in Sweden runes were used until the middle of the nineteenth century in Dalarna and Hälsingland. See Svenska språket under sjuhundra år by Gertrud Pettersson for a full academic dissertation on the subject.