Google's four golden signals for application performance monitoring (APM) and site reliability engineering (SRE) are latency, traffic, errors, and saturation. Latency measures the time between a request and its completion, traffic measures the demand users put on an application, errors measure the total number of requests that fail, and saturation represents the percentage of the system being used. Monitoring these signals provides insights into the health of an application and helps detect issues before they affect users. New Relic offers pre-built golden signals dashboards and alerts to help monitor these signals, including response time, throughput, error rate, average CPU usage, memory usage, and saturation metrics. These dashboards can be customized and integrated with other monitoring tools to provide a comprehensive view of application performance.