Oh yay I'm glad there's good Iceman content out there!! He's often been underappreciated by canon (if not by fandom).

The Stiefvater books are classified as YA though i think the current fandom/readership is a bit older, if only because the first one came out in 2012 so even teens who started reading the books when they were new are adults now.

The first one is called 'The Raven Boys.' There are also popular audiobook versions if that's an easier way for you to read. Do let me know if you give them a try I have So Many Thoughts.