Effective server monitoring requires the right combination of tools and alert thresholds. We cover: Prometheus + Grafana for metrics collection and dashboards, Alertmanager for PagerDuty/Slack integration, node_exporter for system metrics, setting meaningful CPU/memory/disk alert thresholds, creating runbooks for common alerts, and avoiding alert fatigue. Includes a ready-to-use docker-compose setup and Grafana dashboard JSON.