This document provides a crash course on open source cloud computing. It discusses the key characteristics of cloud computing including on-demand self-service, broad network access, resource pooling, rapid elasticity, and measured service. It also covers the main cloud computing service models (SaaS, PaaS, IaaS), deployment models (public, private, hybrid clouds), and the need for architectural design when using cloud computing. Finally, it recommends several open source tools that can be used to build private clouds, including OpenStack, CloudStack, Eucalyptus, OpenNebula, Xen, KVM, GlusterFS, Ceph, and various provisioning, configuration management, automation and monitoring tools.