I pulled this from Stack Exchange but thought it would be useful to share
Classic - INSERT:
ContentVersion before insert - no ContentDocumentId
ContentDocumentLink before insert - LinkEntity = current user
ContentDocumentLink after insert - has Id
ContentVersion after insert - has Id, ContentDocumentId
ContentDocumentLink before insert - LinkEntity = object
ContentVersion before update - Publish status changed from R to P
ContentVersion after update -
ContentDocumentLink after insert - has Id
Classic - UPDATE:
ContentVersion before update
ContentDocument before update
ContentVersion after update
ContentDocument after update
Classic - DELETE:
ContentDocument before delete
ContentDocument after delete
LX - INSERT:
ContentVersion before insert - no ContentDocumentId
ContentDocument before insert
ContentDocument after insert
ContentDocumentLink before insert - LinkEntity = current user
ContentDocumentLink before insert - LinkEntity = object
ContentDocumentLink after insert - LinkEntity = current user
ContentDocumentLink after insert - LinkEntity = object
ContentDocument before update - Publish status changed from U to P
ContentDocument after update
ContentVersion after insert
LX - UPDATE:
ContentVersion before update
ContentDocument before update
ContentDocument after update
ContentVersion after update
LX - DELETE:
ContentDocument before delete
ContentDocument after delete