macOS Public Beta is now active, however; there are many articles out there telling users how to signup then leaving them short of getting the actual update.
I have been checking for days now and the update would not show up.. So I dug around and found the installer.
Let’s go through the entire process for those that have not gotten to it yet.
Enroll your Mac:
Head over to https://beta.apple.com and register your device
Once you are there you will want to Download the macOS Public Beta Access Utility and install it.
This step is VERY IMPORTANT, make sure that you have a backup of all your important files and have a Time Machine backup.
Download and install the Beta:
There you go; going forward, your updates will show up in the Mac App Store under the Updates tab.
Easy as 1, 2, 3 ..
Now go enjoy your High Sierra BETA.