AWS Certified Developer-Associate Level. Examination preperations

I want to prepare for AWS Certified Developer-Associate Level Exam. I've gone through various websites but i am unable to find any proper guidance as to how to prepare for this exam. Those who've written this exam, can you please share your experiences regarding the same. I am not asking to share questions/Patterns of questions. Just a suggestion on how to proceed with my preparations for the same, and what services should i explore in details, etc.

Thanks in advance