Signup for a prerelease org: https://www.salesforce.com/form/signup/prerelease-winter18.jsp
Release Notes also available: https://releasenotes.docs.salesforce.com/en-us/winter18/release-notes/salesforce_release_notes.htm
Signup for a prerelease org: https://www.salesforce.com/form/signup/prerelease-winter18.jsp
Release Notes also available: https://releasenotes.docs.salesforce.com/en-us/winter18/release-notes/salesforce_release_notes.htm