https://cloud.google.com/terms/sla lists uptime and potential credit if Google does not meet SLA on the specific product. Reseller has 30 days from time of missed SLA to submit a credit request. Maximum credit = 50% of the invoice for the month the missed SLA occurred.
https://cloud.google.com/terms/services short description of the product categories and services within Google Cloud Platform.
https://status.cloud.google.com/ shows current service status and past incidents