...

Here are some resources that can help you understand the art of reading blueprints like a pro:

Books

The de-factor reference for learning how to read blueprint is and has been “Blueprint Reading: Construction Drawings for the Building Trade”. You can get it from Amazon: https://www.amazon.com/gp/product/0071549862

Another great read (also available on Amazon) is Hammer's Blueprint Reading Basics: https://www.amazon.com/Hammers-Blueprint-Reading-Basics-Charles/dp/0831136146

Online Training

Here are some awesome online resources:

...

https://www.archtoolbox.com/design-document/construction-documentation/

Videos

And if you’re a “gotta watch how it’s done” sort of person, here are some great YouTube videos on the subject:

...