So the main series is

• Storm Front
• Fool Moon
• Grave Peril
• Summer Knight
• Death Masks
• Blood Rites
• Dead Beat
• Proven Guilty
• White Night
• Small Favor
• Turn Coat
• Changes
• Ghost Story
• Cold Days
• Skin Game
• Peace Talks (not out yet)
• Mirror Mirror (not out yet)

These are the "core" case files The majority of the short stories can be read in the Dresden Files anthology book "Side Jobs" They take place throughout the core series of books but if I remember correctly all but "Aftermath" can be read whenever. DO NOT READ aftermath until you've finished Changes. For the rest If I remember correctly Cold Case is in Shadowed Souls Don't read this until after cold days at the very least. Working for bigfoot also collects the three bigfoot short stories in those anthologies and packages them up too. You can read these to be a completionist, but they do not have a huge impact on the core series.
The Even Hand short story in "Dark and Stormy Knights" is from Marcone's perspective, you don't really need this either but it's a great read as it lets you better understand one of the more predominate frenemies in the series.
"Bombshells" in Dangerous Women is another short story you should get but don't read it until after you read "Ghost Story".
"Jury Duty" in Unbound is another short story you may want to get but do not read it until after "Skin Game"
"Day One" in Unfettered II is one you will probably want to get but again do not read this until after "Skin Game" "Fistful of Warlocks" in Straight Outta Tombstone is one you may want to get but I'd recommend you not read it until after reading "Dead Beat" -Forgot to say, this releases on July 4th of this year. All of these will probably be rebundled in the second Dresden Files anthology "Brief Cases" but no one knows when that will release.

Then we come to the comics, those are canon too. Here's that list

• The Dresden Files: Welcome to the Jungle -prequel to Storm Front
• The Dresden Files: Storm Front- A direct adaptation of the first book you can take it or leave it really since the book goes into more detail, the artwork is nice though.
• The Dresden Files: Fool Moon- Same as above really it's a direct adaptation of the second book.
• The Dresden Files: Ghoul, Goblin- it's set between Fool Moon and Grave Peril.
• The Dresden Files: War Cry- it's set after Dead Beat, but there's a massive spoiler on the last page for the book Turn Coat, you may want to wait until after you read that book to read this.
• The Dresden Files: Down Town- It's set after Proven Guilty
• The Dresden Files: Wild Card- It's set after White Night

That's about it, there's an RPG that's damn fun so if you like that stuff I'd recommend it, but it's also not needed. Let me know if you have further questions.
That should cover the whole series so far.