this morning I have passed AWS CSAA with 95% . I have read a lot ...aws user guides and whitepapers.
and the official guide. But the 8 whizlabs Practice Tests is a must. The practice tests is nearly like the real exam and very helpful to study, because whizlabs gives you a great explication of each right question and links to the aws docs
my tips: To pass the exam, you have to focus in how the services relation each other , and how the services relation with vpc and regions, AZ,etc..
Make real labs with the aws free tier
the exam didnt contain any question about limits o weird cli commands you had to remember . Only you have to focus in a depth understanding of the architecture.
PD:sorry for grammar mistakes , english is not my mother tongue.