Resource:
Trust.salesforce.com - https://trust.salesforce.com/en/
Resource:
Enable Lightning Runtime for Flows- https://resources.docs.salesforce.com/rel1/doc/en-us/static/pdf/salesforce_cloud_flow_designer_guide.pdf
Resource:
Flows on the AppExchange - https://appexchange.salesforce.com/appxStore?type=Flow
Lightning Flow Sample Pack - https://appexchange.salesforce.com/appxListingDetail?listingId=a0N3A00000FAB4hUAH