I work at AWS. I'm someone who helps enterprise customers troubleshoot IAM every day. I also teach new hires, external people, and provide continuing education for IAM.

The biggest thing is what do you want to learn and how complicate do you need things to be. These two reInvent videos are really good:

https://www.youtube.com/watch?v=YQsK4MtsELU https://www.youtube.com/watch?v=Zvz-qYYhvMk

They're a little old and might not talk about the newest and greatest things (like IAM Access Analyzer), but the basics of IAM are there and always stay the same.

If you give a better understanding of what you struggle with (basics, conditions, etc.), we could probably give better answers.

Here are some other reInvent videos I skimmed that look pretty good:

https://www.youtube.com/watch?v=XO4CALyzbVM https://www.youtube.com/watch?v=BFrWnKZ0DQ8

Cloud Academy has some good stuff about AWS. But most re:Invent sessions are on YouTube. You can learn a ton of stuff from re:Invent sessions.

Have your tried reading the AWS docs? As in actually spending some time to read the whole content? They have good descriptions, many guides, step-by-step instructions for simple examples, etc. You can go a long way with just those pages.

If you want something more hand-holding, A Cloud Guru courses are pretty good.

The training offered on aws.training may be a good place to start: https://www.aws.training/LearningLibrary?&search=iam&tab=vie...

What are you trying to figure out? I will say IAM seems daunting because it's used by every other service; you don't have to know what every property or policy is in order to effectively secure your resources.