My MacBook Pro turns on and only shows a folder with a question mark and blinks. The computer will not continue start-up. Suggestions/Advice?

I'm not sure how this screen is appearing, but I tried powering up my computer this morning and it immediately presents a grey screen, then displays a blinking folder with a question mark in the middle of it.

I am looking for troubleshooting advice and procedures to bypass this screen and allow my computer to complete it's start-up.

Thanks-

Gary D. Aston, Jr.

garyastonjr@gmail.com