Like the subtitle says, Jim Butcher’s Side Jobs contains “stories from the Dresden Files.” Here are the minor adventures of Harry Dresden, ranging over his career from before Butcher wrote the first book all the way through a little coda to the most recent book.
Most of the stories are slight; a couple of them were little promo pieces for pamphlets or something, apparently. But it’s not like people come to Dresden books looking for super-heavy epics, anyway, and Butcher is always an engaging writer. If you’ve been reading the series and enjoying it, you’re likely to enjoy this, although almost certainly not as much as you’d enjoy a full-on novel.
As a side note, one of the novellas in this collection was published independently by Subterranean Press for some extortionate price like $30. I almost bought it by accident (I thought it was a real book when I saw it on Amazon, where you don’t get that instant “this thin thing is not a real book” feedback), and am pleased as punch that I managed to avoid getting ripped off. So from a value perspective, this contains a novella that sells for some multiple of the price of the whole collection: What a deal!