Login to Gmail account or create a Gmail account if you don't have one
If no business listing, create new listing under Gmail account. Go to google.com/business to create new listing
Follow the instructions to setup a new listing and fill out as much information as you can.
Verify listing by phone call or post card
If verifying by postcard, it will come in 7-10 days
Once you get postcard login to your Google my business and there will be a red box saying verify now that's where you will put verification PIN in.
Once verified add cover photo, profile picture, and any images that will fit.
Finish adding information about your business such as hours, images, about, etc.